i know Rick Steves recommends it but is aero "worth it"?

You've asked a good question and have a good understanding of the pros and cons of an excursion to Ærø.

I only stayed one night on Ærø, and it did require a lot of travel time. I got there about lunchtime, and spent the afternoon enjoying Ærøskøbing. That's all the time that's needed. I arranged a bicycle rental that afternoon for the next day. The next morning I got up at the crack of dawn and did Rick's recommended bike tour around the island. I really enjoyed that. My ferry left at 11:45.

When I left, I got to Kalmar, Sweden, all in one day. (Ferry to Svendborg, train to Odense, train to Copenhagen, and third train to Kalmar, arriving quite late. It was a long day, but definitely doable. You don't say where in Sweden you are heading to, but if you don't really want to spend a night in Odense, you might be able to get where you're going in a single day.

Was it worth it? I would say yes, but I wouldn't say it's a "must see." There's very little to do there, just a pleasant place to spend a day or two. I can't really say whether it would be worth it for you, and not knowing your complete itinerary, I can't say if there's an alternative that would be more worthwhile and less of a detour.

I am going to Kalmar as you did. Odense is there as a stopover to minimize the long day you had (is Odense"worth it" or should i go straight as you did? I guess i can ask that question about every place).

I didn't stay in Odense, so I can't say if it's worth it. I had about an hour there between trains, and I spent it in the library (right next to the train station) writing a blog post.

You'll love Kalmar. But if you have time, rent a car and drive across the bridge to the island of Öland. I spent a day exploring just the southern half of the island. A lot of fascinating things to see.

If you haven't been to Odense before, I would spend three nights there. And remember to visit "Hans Hule Hånd" ("Hans Hollow Hand")

What does the full itinerary looks like? While Ærø certainly is nice, it is a bit overrated on this site in my opinion.

so sorry for the late reply

the full itinerary is:

day 1 - land in copenhagen at 2:30 PM

day 2 - copenhagen

day 3 - copenhagen

day 4 - copenhagen

day 5 - day trip to malmo/lund

day 6 - day trip to helsingor/helsingborg

day 7 - copenhagen to roskilde (sleep there)

day 8 - roskilde to aero

day 9 - aero

day 10 - aero to odense (leave as early as possible)

day 11 - odense - long day trip to hamburg

day 12 - odense to kalmar (not sure if i should book early train or late train)

day 13 - kalmar

day 14 - kalmar to stockholm (earliest train)

day 15 - stockholm

day 16 - stockholm

day 17 - stockholm flight out

Now that I look at it, it seems like a lot of copenhagen and not enough stockholm? odense day trip to hamburg is a long day also and not sure it's worth it. Given how there does not seem like much to do in aero, how would this change look?

day 8 - roskilde to aero (as early as possible)

day 9 - aero to odense (as early as possible)

and then I'll have an extra day to add somewhere, probably stockholm

Thank you!

I'd suggest that you skip the day trip to Hamburg, it's too far for a day trip in my opinion. You could also rearrange the trip a bit. You can consider not sleeping in Roskilde, yes it would mean backtracking to Copenhagen but saves a one night stay. There are pros and cons of both options.

And, it was my trip I'd suggest you skip the day trip to Lund and Malmö from Copenhagen and instead spend a night in Lund between Ærø/Odense and Kalmar. That would break up a rather long trip. If you're trying to avoid one night stays, spend two nights in Lund and do Helsingborg/Helsingør as a day trip from Lund instead. And skip Malmö unless you have a great reason to go there.

From Kalmar to Stockholm there are two options for the train, either with a change in Alvesta or a change in Linköping. My recommendation is to choose the option via Linköping, it's a bit more scenic in my opinion. And yes an extra day in Stockholm is not a bad idea.

An extra day in Stockholm is never a bad idea! I added an extra night in 2022, and I had started with eleven. I'm going back for a few more days this summer to see things I missed. I can't compare it to Copenhagen since I haven't been to the latter in 50 years; I'm sure I'll end up with a lot of days in Copenhagen on a future trip as well.

I think you might have enough time in Kalmar with a late train from Odense. I spent 3 nights (2-1/2 days) in Kalmar, but it was more time than I needed, and I am an exceptionally slow traveler who walks every street in the historic district in a town like Kalmar. I'm not generally much for castles, but I did go to Kalmar Slott, and I spent a lot of time there because I read every word of the special exhibition then running.

I haven't been to Aero so can't comment on it. However, I jumped through a lot of hoops, including spending two nights in the town of Oskarshamn, in order to have 36 hours in Visby on the island of Gotland, and I didn't regret it.

it's clear to me now i did a bad job planning and changes things too much will be expensive. oh well.
how's this:

day 1 - land in copenhagen at 2:30 PM
day 2 - copenhagen
day 3 - copenhagen
day 4 - copenhagen
day 5 - copenhagen to roskilde to aero in evening (is this possible? Is there a place to put luggage in roskilde?, only one bag)
day 6 – aero for the day
day 7 – aero to odense (leave as early as possible). Does anyone know how long this takes?
day 8 – odense to hamburg (i don't think hamburg is must see or anything but it seems like I have the extra days to waste since I cant move them to stockholm)
day 9 – hamburg to odense
day 10 – odense to lund (early or late train?)
day 11 - lund day trip to helsingor
day 12 - lund to kalmar (late train)
day 13 - kalmar
day 14 - kalmar to stockholm (earliest train)
day 15 - stockholm
day 16 - stockholm
day 17 - stockholm flight out

as I said, I dont think i could add days to stockholm. Given the flight departure time, it seems like I'll have 3-3.5 days so it's actually not too bad but it feels like i should have moved a day or two over there and done some day trips from there instead of only doing them from copenhagen area.

Helsingborg has some attractive architecture in the center, but it's the rare city where I have needed less time than expected. I day tripped there from Malmo, which has some not-great modern architecture sprinkled around the center but does have some museums I enjoyed. Obviously, your interests may vary. I skipped the Dunkers Kulturhus in Helsingborg, which I believe is a good museum.

I mention this because you're going to Helsingborg from Lund, which is very attractive but not terribly large. It might be a good idea to see whether any of the towns the train passes through between Helsingborg and Lund would be worth a stop of a few hours.

I was impressed by the food offerings in booths gathered at an outdoor area I encountered in Helsingborg; they were not the usual offerings. I believe this was on the northeast side of the main street (Jarnvagsgatan/Drottninggatan) as you walk NNW from the train station. It may have been Stortorget. You won't be able to miss it if you do much walking around if, as I suspect, the stands are set up every day of the week. I did see one booth that accepted only cash or some sort of electronic transfer.

hmm, in general, it seems like i'm spending too much time in the copenhagen area (which to me includes, Lund, Helsingor, etc). I'm also not that slow a traveler though i do like museums. Hopefully the time i spend in stockholm will be enough and i won't regret my planning.

Helsingborg has some attractive architecture in the center, but it's
the rare city where I have needed less time than expected.

It depends a bit on what you are interested in, but personally I like Helsingborg. For a summer trip, you must include a visit to Sofiero palace just north of Helsingborg.

It might be a good idea to see whether any of the towns the train
passes through between Helsingborg and Lund would be worth a stop of a
few hours.

The only real town inbetween is Landskrona, where there are some things to see. But more important is the gateway to Ven.

I just found out there's a hamburg-malmo night train (as part of a berlin-stockholm night train) so going to hamburg won't require hamburg->odense and then odense->lund but could just do hamburg->malmo->lund through the night. Does taking that night train change anyone's opinion on whether i should try to fit in hamburg?

It could be something like one of these two:

day 1 arrival in Copenhagen
day 2 Copenhagen
day 3 Copenhagen
day 4 Copenhagen
day 5 Copenhagen to Roskilde to Odense or Aero
day 6 Aero to Odense (or aero day trip from Odense)
day 7 Odense to Hamburg
day 8 Hamburg with night train from hamburg to malmo
day 9 lund day trip to helsingor
day 10 lund
day 11 lund to kalmar
kalmar/stockholm/flight home etc.

day 1 arrival in Copenhagen
day 2 Copenhagen
day 3 Copenhagen
day 4 Copenhagen
day 5 Copenhagen to Roskilde to Aero
day 6 Aero
day 7 Aero to Odense (early)
day 8 Odense to Hamburg (early)
day 9 hamburg - take night train to malmo
day 10 day trip to helsingor from malmo/lund
day 11 lund during day and then later train to kalmar
and then kalmar/stockholm/flight home etc.

I just found out there's a hamburg-malmo night train (as part of a
berlin-stockholm night train) so going to hamburg won't require
hamburg->odense and then odense->lund but could just do
hamburg->malmo->lund through the night. Does taking that night train
change anyone's opinion on whether i should try to fit in hamburg?

Not really. As you mentioned it is the Hamburg-Stockholm night train so it arrives very early in Lund and even earlier in Malmö. But if you don't mind a 4:35 arrival in Lund, then yes, it would work and save you a bit of travel time.

does anyone know if Lund-Helsingor or Lund-Malmo are cheaper if booked in advance?

Or if roskilde-aero or aero-odense are cheaper if booked in advance?

Thanks

I'd suggest buying Roskile-Ærø (Svendborg) in advance, the rest can be bought in advance but I don't think it is worth it.

Our family visited last summer and felt Aero was not worth it. We all said we should have skipped it and spent that time elsewhere. As you and others have pointed out it is not terribly quick to get to.

We took a train from Copenhagen to Odenense to Svenborg. We took the ferry over to Svenborg for the day and rented a bike. The bikes have seen their better days and we felt Rick's maps in the guidebook could be improved. We got quite lost many times. And while Denmark is a lovely biking country Aero we found was not all that bike friendly in our opinion. We found a lack of bike lanes and cars/trucks going at high rates of speed made for some dicey situations. I think our biking experience could have been better with better maps and better bikes. We knew there was not going to be a whole lot going on in Aero but we were very surprised at how little there was to do for a place Rick pushes so much. I'm not sure what the draw is. And please know we are a family who normally bike and go to islands on vacation so this is an environment we typically enjoy.

We stayed overnight in Svendborg as everything on Aero was booked in advance of our trip. That's a decent option for those that feel they must visit Aero but can't get lodging there. At least you are close to the ferry that way. But truly this is an entire part of our trip that we could have skipped.

As you did, I'm doing a day trip to Aero from svenborg on Monday. There was lodging at aero but the lodging in svenborg was just way cheaper. If you didn't like Aero given how you normally like chill bike-on-island trips, I think I won't be too crazy about Aero either and will end up feeling similarly to how you felt. Oh well. It's really only a day that I am spending on Aero and if nothing else hopefully it'll be a nice change of pace for a bit.