You wanted to said 2.23 servers. It depends what do you mean when you said ''A fun server''. Some peoples would like to play tests, hotels, battles with one life, lrs, duels etc. Old is pretty much said. ''Old'' servers (like you're coop episodes) are and will be. Personally, I hosted JJ2 adventure levels (all) from 2.23 2 days ago. And just to know, races have bugs at Jazz Online. When someone win a race, he is automatically kicked from server (except for admin). Much peoples said 2.24 players are noobs playing theese ''non-fun'' levels (did I said I'm one of them?). If you don't like this stupid 'attraction', play Single Player or with your friend. Trust me its really more fun than an admin who is doing 'the rules'.
(Sorry for my bad English)