We haven't watched all the special features yet, so I can't comment on all of them. There's a cool 'making of B5' feature that's narrated by Bester, er, Checkov, er, I mean Walter Koenig. There's also a nifty feature that supposedly is the B5 computer's intro to the station.
It's a 6 disk set, and we wanted to get down to watching episodes. Probably won't get more time to watch until Sunday night, so I can post more then if you like.