I really can't decide if I love or hate it, I played it first time, mostly just the main story line, I didn't intend to do that, I just didn't really find much traveling between main storyline stuff, and I always thought of missions/map points I got hints to go to, that I'd go past that at some point in the story and simply never did.
90% of the locations are utterly worthless, offering nothing but ammo/cash that you don't in any way require.
LIkewise enemies not scaling with you is rubbish, if you have all the addon's, after hitting around lvl 25, there will basically be one of the uber high level versions of scorpions or super mutants the majority of places you go, its either guys you can barely kill maxed out, or guys you can one shot with basically any gun in VATS.
Also being a FPS type guy I basically refused to use VATS the first time through and it was needlessly difficult, VATS is basically not an option, especially early on, and with VATS its painfully overpowered making almost everyone ridiculously easy to kill.
Anyway, second play through, I used VATS, did literally everything, and completely regretted it, took ages, did all the DLC< was vastly overpowered and hit lvl 30 with probably 30% of the game done, as said most stuff is so boring but you really don't know which locations will be interesting till you've tried them, which I found VERY irritating.
I think thats the biggest flaw with the game, if you stick with the main story line alone you miss 90% of the content, if you randomly search for the other 25% of worthwhile content, it will take you weeks and be boring.
What I felt after both playthroughs was the main story needed to be MUCH longer and take you basically through all the main locations with bigger quests and towns, while leaving out most of the "filler" rubbish area's theres really no need to go to.
The scale of the game is fantastic, the world, while animation sucked, was brilliantly atmospheric, the city area is well built and lots of indoor area's were great, though some are too vast/long/boring with little reason for being.
New Vegas I can't get into at all, the start is awful, the story, the area, the "tutorial" and the dialogue is several magnitudes worse than Fallout 3.