Krk

I would share your concern and have not been to that island. On the plus side, it is connected to the mainland by bridge, so you won't always be reliant on ferry schedules or ferry crowding. When I did drive myself along the northern Croatian coast once upon a Saturday in August, traffic was jammed with beachgoers from all over Europe. I would feel more positive about the freedom of a car in any month other than August.

Thanks Laura - good to know about the traffic - we're form the LA area so don't need more of that on vacation!

we have been to Krk a few times to visit and swim. We usually look for small piers to swim off as opposed to the beaches. there are small towns to explore and great restaurants. Laura is correct about the traffic on the weekends, but you will be going against traffic. People are driving to Krk from Rijeka, etc. You could plan overnights during the weekends to Istria (Pula, Rovinj, etc) when the island is packed with sun seekers. Opatija is worth a visit, but go in the evening, you need to see it at night when it comes alive. When we were this past July, we noticed more tourist activities, such as parasailing, wave runners, etc. I don't know how many weeks you plan on staying, I am sure you will love it, but definitely plan on other excursions. also, It is very busy during the summer because they have many campsites. Have a great trip.

Thank you fabris!
We are thinking about 3 weeks with side trips to Pula, Venice (a little far, I know, but worth it!), Romijn, and possibly sailing, which I hear is amazing in Croatia. The owners of the apartment have also offered their house in Zagreb for a weekend if we want to use it.
Think 3 weeks is too much?

Personally, 3 weeks on Krk would be too long for us. With the price of airfare, we want more sightseeing for our money. Even though we love going to the beach, we usually go early in the morning (7:30) for about one hour, go back to our room, have breakfast then go out for the day. We might go for a quick swim at the end of the day also, but we never spend an entire day there it is too hot. Zagreb is a quaint, small city and a weekend would be sufficient. If you can, stay for a few nights in Venice it is one of my favorite cities. When we go to Croatia, which is every other year for a minimum of 3 weeks, we travel from Zagreb to Rijeka to Dubrovnik visiting family and friends. we never stay in one city for more than a week.

Again, thank you! Great information.
I think we'll pass on this home exchange then - I had my doubts but you have confirmed what I suspected.
Cheers!

If you want to stay 3 weeks in Croatia, I would stay along the coast, down near Split, korcula, dubrovnik, etc. There is plenty to do around those towns and many side trips to small islands possible.
I don't know your budget, but Katarina Line runs week long cruises down the coast on rented yachts. You can check out their website www.katarina-line.com. We haven't sailed with them yet but We are determined to (last summer the dates didn't work out because we had a funeral to attend and too many family members were with us.) We have spoken to them at their office in Opatija and have seen the various ships in different ports. Hopefully we will get on a cruise summer of 2016.

That sounds amazing!
Really, the only reason we were considering Croatia was because we were offered a home exchange there. This is how we usually travel during the summer so I don't think a yacht trip is in the cards this year. Someday we will definitely do this though.
Thanks again for your help!