I completed MGS 4. (Played that befor but just start of the game). Also this is first MGS I completed. I can say graphics is still good in MGS 4, but for 2008 that was top level. I think only REsistance 2 was better, but that game was released in fall. Also I can compare MGS 4 to Gears of War 2, also released later that year. MGS 4 wins in almost every aspect. Character models have more polygons, have better textures, amazing cloth simulation, (it looks incredible even today), environment also lookes better. I think it have less polygons, bet textures are a lot better, especially metal constructions. MGS have better lighting, and have shadows. This is very strange, but there is no shadows in Gears 1 and 2.
Cut scenes in my opinion better that in 90% tooday games. And in 2008 they were best. I completed almost all mayor games of that gen, and didn't thought what some game from that gen can surprise me.
Also the idea of suit changing colors depending of surface is still only in MGS 4.