Personally, qua raids and and all. I find that Karazhan gives "minor" raid experience. Not many raiding guilds populate the Karazhan server on the alliance side.
also, the auctionhouse is a complete MESS! ive been scouting for a few items and its taking forever to get them.
also, i have found that most of the alliance player on Karazhan(some not all)
are completely retarded sacks of dog poo.
other then that: It aint half bad.