Dubrovnik and Korcula - too much of the same thing in miniature (Korcula?)

I like Korcula and although it's a town on the sea, I feel it was not the same experience as Dubrovnik. It's a nice place for downtime. I spent a lot of time on the beach and relaxing- not that I didn't do that in Dubrovnik- but it's peaceful and so laid back. It's a great escape from the cruise ship crush.

Zagreb is nice-semi interesting. 1 night was enough to get the flavour.

We really enjoyed staying in Bled and having the 5 nights we had there to just enjoy the beauty of the lake. You might consider more time there vs day trip.

Last suggestion-since you are going to Medujorgie- what about Mostar? It was one of my favourite places to visit - you should try to get to Kravice waterfalls too. While I loved Plitvice- you can swim and explore the caves and waterfalls at Kravice- it's cold though. Benefit: no selfie sticks and overcrowded paths. It's basically locals only there.

Your trip sounds great.

I wouldn't cut any nights from Korcula. If anything I would cut one night from Dubrovnik unless you are doing a day trip one day (to Montenegro or elsewhere). Dubrovnik is tiny. You can see it all in one day or day and half. I would make sure you have some time to see Trogir near Split, as well as Mostar.

I did a three-week trip to Croatia, Slovenia, and Bosnia in May 2014. I got tons of advice and found it very hard to settle on an itinerary, as there are so many places worth seeing, and everyone has an opinion, and you can't go everywhere.

The good news is you can't go wrong. The fact that there are so many places worth seeing means that it is very likely that anywhere and everywhere you go will be great!

Dubrovnik and Korcula are not redundant. Korcula is much more laid-back, with a relaxed island vibe and a ton of charm. Dubrovnik is more bustling and visually impressive. Three nights there will give you opportunities for day trips or activities like kayaking. You could travel to Kotor for a day, and Cavtat is not far and can be visited by a short boat ride or by bus.

I second the advice to get to Mostar, since you'll be very close when you're in Medugorje.

I didn't get to the horse farm or to Postojna Cave when I was there. I do highly recommend hiking the Kobarid Historic Trail. Also, heading out of Kobarid toward Istria I stopped at Tolmin Gorge. It was well worth the visit. (Vintgar Gorge, near Bled, was closed when I was there due to damage caused by severe winter weather. At the TI in Kobarid I was told that Vintgar is actually nicer than Vintgar.) I also stopped at Škocjan Caves, and while it was impressive to see, you have to visit it on large group tours. I felt like we were being herded through like sheep and our guide was not very pleasant. Also, photos are not allowed inside the caves.

When you're in Rovinj and taking day trips, my favorite small town was Grožnjan.

Just don't spend too much time and effort second-guessing yourself. You'll have a great time whatever you decide.

Thank you all for your helpful feedback. (Lane) I agree, it's really hard to settle on where to go in this area - even with 2 1/2 weeks! I am convinced to keep Korcula on the itinerary. I do plan to visit Mostar from Medugorje. I would much rather stay in Mostar, but my husband really wants more time in Medugorje. I will be using all your advice as I continue to refine my trip. I am so excited to visit this beautiful and interesting area of the world!

This is somewhat similar to what we did this past summer.
We were happly surprised by Zagreb, an Austrian feel in architecture. A day is enough
Ljubljana is a super nice very small capital that you will walk in about 4-5 hours. This is why we decided to stay in Bled instead an do a day trip to Ljubljana and around..
We saw the lippizaner horse show. If you've seen a similar show in Jerez Andalucia, it's not as spectacular. If you have to choose between a cave and the show, I'd do a cave. I did Skojcan, not Postojna after listening to a Rick Steve radio podcast. He was telling the differences between both and from what I heard I decided to do Skojcan. It was huge! Great expericience.
When you go to Kobarid, if you are a bit into WWI, make sure to see the museum, it's a small, but moving museum. And when you go, try to go there thru the Vrsic pass, it's a nice spectacular road.
If you are into world class restaurants(I wasn't but a friend of mine is) apparently there's a very high-end restaurant in Kobarid: Hisa Franko.
Reviews are unreal.
We stayed 3 nights in Dubrovnik and used one day to go to Montenegro. Too many tourists but an amazing place you can appreciated more before 10am or after 6pm. Just a bit less people.
I think the nights in each places are well laid out
I didn't see Korcula and I somewhat regret.
From Split, Trogir is a nice 2-3 hour visit. Split is great as well.
Plitvice lakes are totally enchanting
If you like nice walks, Velika Planina between Ljubljana and Bled is super nice. You'll feel you've gone back 150 years.

While you can get a taste of Ljubljana and Zagreb in a day each, I enjoyed having more time in both those cities. I spent more than a full day just walking the streets in the historic districts, then both cities have worthwhile museums (substantially more in Zagreb) and daily or weekly markets.

One day's probably right on this 2-1/2 week trip, though, given all the other places one wants to see in the area.