I've never played an Uncharted game until last month when my mate borrowed me the Remastered collection.
The first game I found very dull until about the 4th chapter, then I really enjoyed it for what it was - a popcorn, dumb-fun shooter with a few extra puzzle/climbing/vehicle sections thrown in. It lost it's way a bit towards the end - the vehicle sections were awful, and the puzzle + climbing sections didn't really add much other than to break up the action - but overall it was a fun 7.5/10 experience for me.
However, I'm just playing through Uncharted 2 and it's been fairly bad all round so far (I've just started Chapter 18). The gunplay seems to have de-volved as has the game as a whole. There seems to be countless climbing sections which are dull and predictable as hell (seriously, nothing in the game doesn't break - from chairs, to pipes, to ledges - the whole world is stuck together using sellotape, and it gets tiresome seeing every jump met with a slip or break etc.). There's loads of trial and error, and pretty much every death I've suffered has been laughable due to it usually coming out of nowhere or down to just plain bad design (I don't think I've died once in a combat scenario). So far it'd get a 4/10 from me, and I'm only forcing my way through it so I can play the 3rd installment. They've took a light, fun game and padded it out with gumph it didn't need, throwing near-misses in every other second and removing any tension from the game.
Overall I'm unimpressed so far. Neither games are much more than dumb fun at best; at worst a Michael Bay-esq action movie which mostly plays itself, and has so much going off you switch off to it.