It has been recently discussed in the Ubuntu developer mailing list that gnome-bt should be replaced by a more powerful bittorrent application. The name of Deluge was mentioned, but most participants rejected it because of its "overcomplicated" preferences menu:
What I liked best about Transmission, was the small number of sensible configuration options. Deluge, for instance, uses configuration GUI space to ask if you want to password protect the system tray icon. Who uses that? It's just annoying. Fine, if people want those advanced options, nothing is keeping them from installing Azureus or something like that, but they certainly aren't normal users.
Some users probably would attribute lack of features/options to lack of quality. However the spirit of the Gnome desktop is to have just enough options and sensible defaults. I really can't recommend a client that respects it better than Transmission.
You can find other similar comments on this month's
mailing list. I would like to see Deluge included in Ubuntu out of the box (much more than transmission) but I think it's true that the preferences dialogue could use a facelift, and a great deal of its options should be reubicated to plugin preferences or just replaced by sane defaults.