BOBW is a great 2-parter and Chain of Command & Unification both have great PtIIs but both their PtIs are just OK. The opposite is true for Descent. Time's Arrow, Redemption, Birthright & Gambit are all watchable, but not outstanding.
As such, I don't think the movies have quite such stiff competition with just the 2-parters as they do versus the series as a whole.
I like Generations a lot more than most people (it has a lot of nice little touches throughout, a unique visual look and an interesting story theme despite admittedly imperfect execution) and think it easily exceeds most of the two parters. First Contact is a somewhat dumb but very well-executed action flick with a cool ending; I'd put it ahead of a lot of the two parters too. Insurrection is thoroughly average and Nemesis is dreadful by every measure I can think of.
That means I find two of the four TNG movies very enjoyable and one watchable. Out of the 16 episodes comprising the 8 series 2-parters I find 5-6 very enjoyable and vast majority of the rest to be watchable.
I'd definitely agree that the 2-parters have much more consistency
than the movies, but going solely by my "very enjoyable" category, the movies actually come out slightly ahead percentage-wise. It's a real shame Nemesis was so awful & left such a bad taste in the mouth.
(PS I don't count Farpoint or AGT as 2-parters as they're more standalone double-length episodes rather than episodes designed as 2-parters. I really like both these two eps; if they're included in the 2-parters list, that would certainly be enough to decisively tip the scales in its favour.)