I am reliving my childhood today with the fantastic Metal Gear Solid HD Collection, and I have noticed that the buttons on my XBOX 360 controller(unlike the buttons on my old Playstation 2 controller) don't seem to be pressure sensitive. This is making aiming my Rifle a nightmare, as I'm either not holding it, or I am shooting bullets everywhere!
I think even the original DualShock controller that came out for the original Playstation had pressure sensitive buttons. Does the XBOX 360 controller not have pressure sensitive buttons? Or has the game just been badly ported from the PS2?
The Xbox 360 controller does not have pressure sensitive face buttons. The only pressure sensitive inputs are the analog sticks and the triggers. The issues this causes for games developed for other platforms is a common complaint - notably Metal Gear Solid games, as you've mentioned.
Wikipedia even mentions this in their article about gamepads:
[On the Xbox 360 controller,] the pressure-sensitivity feature on the face buttons was removed, making some original Xbox games, such as Metal Gear Solid 2, unplayable.
MGS2 was ported the original Xbox and its controllers buttons were pressure sensitive but since very few games used it when It was time to make the 360 Microsoft removed it. So the 360 does NOT have pressure sensitive buttons like its predecessor.