...That I haven't really played it yet.
I decided to go back and play through the previous games first. I never finished MGS3 and I barely touched MGS2. Two weeks ago, I went back to MGS3 Subsistence. Started with six hours logged in, and finished it in about 14. It was a fantastic game, and for a Metal Gear title, the story was more grounded in "reality." I much prefer it to any of the later nanomachine-filled sci-fi bullshit. The ending also destroys MGS4's, which is really not hard to do. (I don't like constant retconning.) Also been playing Portable Ops. It's frustrating, because there are times when I want to sneak up on someone and grab them, but the character punches instead. The game definitely has some frustrating controls and it has made for some hair-pulling experiences. I generally give a mission one or two chances and then shut the game off for the day. Don't think I have much left to play through in it though.
Yesterday I started playing MGS2 Substance. Two things- I already miss Big Boss and I miss the more modern control and camera schemes much, much more. Raiden still sucks. His voice sounds even worse than I remember it. But I'm going to plod on finish the game. After that, I'm still not sure if I'm going to play MGS4. I may be doing this out of chronological order, but I think I might play through The Twin Snakes first. I never did finish that one either.