Ambassador - I've never really liked the ship for role-playing or otherwise. However, I think it needs to be in the game to complete the Enterprise line.
Sovereign - I love the ship (and own it), but the Excelsior Refit is my baby. Whoever put that into the game has my eternal gratitude. Perhaps they should come out with a tier 6 Sovereign for when Cryptic raised the current rank cap.
BOFF uniforms - I also wish that you had the option to use a special BOFF's uniform or change to match your away team. I think that's a nice option on the Borg Engineer.