I just beat the game. 17:34 time, Solid Normal, rank of Eagle.
Commentary:
Good game. Story is as on par with the others. Though some of the resolutions and answered questions felt less than necessary, but they went the completionist route. Gameplay could have used more time in the stealth on a battlefield. In my 17:34, I think about 6 of them were done playing that. Maybe 7. My time could have been shorter, of course, I spent a lot of time with the bosses. I have a couple of complaints relative to previous editions, neither of which I wish to spoil. But I will say that you may or may not find the 'twist' to be less exciting than previous games. And it's felt like it was lacking something critical to the series.
Everyone's a critic, I know. But it was still tons of fun. It's not my favorite MGS game, but it's still one of the best games I've played in a while. I'm about to play it through a second time if that's worth anything. More specific commentary can be found in the spoiler thread.