I've not done Croatia with JY but have done Iceland twice, enjoyed it so much I went back! Wherever you go with JY I think you will enjoy yourself. You meet like minded people, varying ages, and get to see some wonderful places. I've done several tours, and got two coming up this autumn. I've never not found a friendly crowd, but there is always time for yourself, if you choose. Hope you enjoy whatever you choose, then book the other for your next trip!