Completed it last night (not done it on hard, or any side missions yet).
I loved it. It's worth noting I also got my PS4 last night so was also getting used to the new 'shiny' of it.
But yeh, gameplay wise superb

Unfortunately I'd seen pretty much all the cutscenes in some form through trailers, but there isn't much of them anyway. The controls are great though, Snakes actions are very fluid and the options are vast... though I miss knocking on walls! Also the lack of David Hayter was pretty noticable... snake probably sounds a touch younger since Peace Walker.
It took me a couple hours, and lot's of restarting as I'm a perfectionist. I will certainly be playing this many times over to see the different possibilities.
It's also very playable through the Vita's remote play which is awesome.
Pretty much the same. PS4 is at 1080p while XBone is 720p. PS4 has an exclusive MGS1 Deja Vu mission, while XBone has an exclusive Raiden kinda mission. There are trailers for these you can check out.