I can''t respond with any experience. However, I have signed up for a floatilla in Croatia in May with Sailing Holidays, and I''ve ordered the following from www.imray.com:
Imray Chart M23
Imray Chart M234
Delius Klasing chart pack Adria II
Navigational Guide to the The Adriatic Croation Coast
The guide seems to be a good as the Heikell guides.
FYI, I''ve found what seems to be the entire text of the quide online.
If you go to www.sailingholidays.com, you can see at a high level the various courses they follow.