This time around I beat MGS2 in a little over 8 hours on normal watching all the cutscenes. MGS3 definitely takes longer. I'm 4 hours in and I just got outta the cave. It's probably because the sentrys in MGS2 are for the most part deaf to footsteps.
Its weird for me almost every first playthough of a mgs game it takes me about 12hours and almost on the dot for every game so for example 12.01 and 12.06 its quite odd indeed, I don't try and play them so i end on 12 hours it just happens lol. P.S not on pw tho thats like 33hours or something lol.