The best game I've ever played. Can't get better.
Some downsides are that despite the story being good, it can be confusing at times. Cut-scenes can last for ages, and although they are great to watch, they can be a bit boring to be honest.
By the way, a new feature in MGS3 is that you can wear different camo, depending on your background. The controls are altered slightly and are much easier to use.
Finishing off, the replay value is as good as I said before. I've finished it 18 times and I'm still not bored!