The main journos here in Spain watched it yesterday and according to them, it isn't that bad. The bunch I talked to this morning included a comic books connoisseur -who didn't exactly like it- and some other uninitiated, except for having seen the previous 2 movies which they consider "mainly good".
Not that they're entirely trustful, but I'm afraid they'll be more in tune with Joe Public that we will get to be. Apparently, they were missing more "superheroic stuff" this time around but were pleased with "the nice FX" (hmmm) and "colorful characters". Oh, and Brett Ratner behind the lens didn't bother them much, although many of them didn't know who he was (ah, the spanish press...)
So all in all, and expecting good reviews from their camp, looks like Fox has a moderate hit in their hands here.