With cost in consideration, Battle.net is a great multiplayer service.  Most of the time I get 140-150ms ping to their servers, on 56k.
I thought it didn't matter what your connection to the Bnet server was?  I thought all that mattered was your connection to the other people.
Anyway, it's possible that your T1 is at fault here, because most of the time it's fine... Sure I've complained, but I'm on a 56k!  I don't think I'd complain even on Cable!
Cretin