I returned yesterday from my sixth charter in Croatia. Maybe it's the economy, but I found it much less crowded than previous years. We were at anchor all but two nights - one in Zut to recharge the batteries (lovely Marina in a bay) and one in Piskera due to a storm warning. We had wonderful winds F3- F6 and the nights were cool for sleeping.
There is a lot of competition in Croatia and you can get some really good deals. I have mainly used Sailing Croatia - yacht charter Croatia - sailing holidays - MiramoClub
as they have a very nice search engine to see what is available they have their own fleet but also act as agents for other companies, so you have to check out who the boat is being chartered from. We got a 2008 Bavaria 46 for 2,300 Euro in high season.
I've never had a bad experience, just a few niggles. We had a problem with the fecal tank and they sent three guys in a speedboat who were there in an hour. (Rather them than me on that job). I asked for extra mooring warps and this was no problem (BTW if taking a line ashore, do tie to a rock not a tree as it wears the bark, also make sure you have swimming shoes as the rocks a razor sharp in places)