You guys should try playing the game on Extreme (there is an Extreme difficulty, right?)... I did that on MGS2 (while trying to get all the dogtags, too) Once you get used to where most of the enemies are it's not too hard,
but there are certain sticking points, especially boss fights, that can really be frustrating. I had to fight the last boss with a
slightly less-than-full bar of life and only one ration
After I beat MGS2 on Extreme, I looked back and thought
"Wow... I can't believe I took the time to do that and I didn't even get all of the #%$&ing dogtags!"
And I look forward to doing it again with MGS:TS...
