It's easily, in my opinion, the most over-rated film in the entire franchise.
TUC has always been my favorite Trek since the day I saw it. It is a great little "whodunit" that just happens to be set in space.....they finally had the sets redressed and looking beautiful, I loved the clock above the viewscreen so we could keep track i real time. I love the cut that includes the conspiracy.....and they "target that explosion and fire" scene with the Enterprise/Excelsior tag team might just be my favorite fan boy moment ever. Oh and that dinner party was great too.
This does go to show you different people look at things sometimes in vastly different ways. What one person thinks is a strength another sees as a flaw (and vice versa).
My opinion of TUC has actually gone down a bit over the years. When I first saw it in the theater I was impressed and thought it was a great film. I admit part of that was my excitement at seeing one more original series film at a time when Star Trek was starting to gain steam, with TNG coming into its own at the time.
But in the cold light of day now? It doesn't hold up as well for me. Of the 6 original series films I probably would rank it around 4th or 5th place now, whereas initially I probably had it in 3rd place.
For me TMP in 1st place and TWOK in 2nd place (out of all 13 films in that case) has never changed. But now, for the first 6 films I'd probably have TVH in 3rd place, TUC in 4th, TSFS in 5th and TFF in 6th place (and 13/13 overall). Throw in all 13 films and my middle films tend to fluctuate a bit, though First Contact is always my 3rd place film overall and Insurrection is always 12/13 overall (if they ever fixed the awful effects in TFF I would switch it with Insurrection--yes, they are so bad I actually knock it down a peg just for that

). Though as I always say, I don't hate any Trek film. Even though Insurrection and TFF are at the bottom of the pack, I still enjoy watching them when the mood strikes. And interestingly enough, opposite to TUC, I find I've liked TFF a bit more as the years have gone on. Not enough to move it out of last place, but it's a fun film to watch in some ways.
There are things I still like about TUC--I always like a good mystery, the intrigue, trying to figure out the bad guys, though I agree with Vger23--Valeris was pretty easy to pin down and I just never cared for that character all that much. I also liked the final battle and the buildup of suspense as you see the assassination plot unfold against the space battle, which was pretty well done. The music score was pretty good, though Goldsmith and Horner would still be my top picks for scores. I do agree with some of the criticisms about Chang, though Plummer does the best he can with the role IMO and I can't help but like his performance despite the character weaknesses (plus, I admit I do get a kick out of the patch nailed to the head--that is one thing I can definitely see Klingons doing

). But the weaknesses of the film that I've mentioned in the past continue to be an issue for me. And there still seems to be a bit of carryover of the silly humor from TFF at times (like the goofy translation scene--which would have fit right in with TFF).