I think it was the care given to their little bits and after seeing all these missed opportunities I think it would be a major step in line with Trooperman's intention to get more "OT" if the droid stuff could be brought up to snuff.
C3P0 is harder to deal with because his dialogue was witty in the OT and clumsy in the PT and that's hard to improve with editing. Artoo, on the other hand, has no dialogue. He has stuff that is almost charming, like getting told he can't pick up food at the counter -- but it's tossed off in a "been there done that" way compared to similar beats in the OT. That's why they don't carry the day.
The thing to achieve is giving Artoo a stronger sense of p.o.v. ANH tells a story from beginning to end from their p.o.v. and the OT maintains that sub-story pretty well. But TPM never did any good droid p.o.v. beats with the possible exception of Artoo's first meeting with Threepio.
SOTD has at least these two opportunities to build scenes around Artoo's p.o.v. Given the contrast between that opportunity, or sticking with the stilted character stuff that's there already, I can't help seeing this as more than a "meh" kind of issue.
--and come on, how great would it be to start the movie from Artoo's p.o.v.? That scene on the landing deck is powerful image-wise, but totally balls with Padme's "oh my gosh, I'm so unable to move because I'm so shocked" routine that requires a totally stiff Typho to goose her into action. Remove Typho, let Padme be a self-starter, and start it all by locking us into Artoo's p.o.v -- that's what a Prequel opening scene is supposed to be!