They are the same. BitTorrent Inc. bought the uTorrent software and built their new BitTorrent software on the uTorrent code abandoning their open source mainline client. So both programs share the same codebase and should therefore have the same features.
I think it was part of the deal that when BitTorrent Inc. bought uTorrent, the uTorrent client, website and community would remain. BitTorrent in return got a very good client and a large community of users in the uTorrent community. The other stipulation I think was that uTorrent would not release it's code as open source like BitTorrent's original mainline client.