I'm usallly one that likes extra scenes in movies, but in this case I think they hurt the movie rather than add to it.
None of the additonal material adds anything of substance to the film, and only serves to slow/break up the pace IMHO. Scotty's "that Klingon bitch" dialogue is just horrible. The theatrical is indeed the superior cut.
The TUC Blu-ray is the finest AV presentation of the movie currently available on home video, and has the virtue of being the only one with the theatrical version - in its original aspect ratio to boot!