So I played it, or at least tried to play it, a couple of months ago. I was coming from my 10th replay for MGS1. The first part with Solid Snake was THE PERFECT sequel. The upgrade in the gameplay mechanics is phenomenal. The game played super smoothly, and controlling Snake never felt better.
And then.....
The second part began, Raiden was, is and will always be the worst main character in a game ever. And if that wasn't enough, the game takes a sudden turn into shitty sci-fi characters, long boring and useless codec conversations, an even more boring and stretched cutscenes, horrid voice acting, poor pacing and bad level design. OH MY GOD, how can a game sooooo good, becomes SOOOO BAD in a matter of minutes. I couldn't continue playing it. To me, MGS2 is the biggest F you from a developer.
edit: I'll be playing MGS3 very soon. I hope it holds up better than 2.