dirtydog said:
It should be self-evident why a mouse is inherently better for an FPS game, much as it is for moving a pointer around a computer screen. You can aim exactly where you want, in a split second, with a mouse. It is physically impossible to do that with a pad with the same consistency and accuracy.
It's easier with a pad, not better - in many cases the opposite is true.
In games that focus on twitch aiming and lightning fast reactions the mouse is king - anyone who's played Q3 on the DC will know this all too well. Games that focus on taking your time and aiming, imo, work far better on a pad.
Why is Golden Eye so fondly remembered, even by many hardcore pc fps fans, after all these years? Because taking your time to line up each shot felt more real, more deadly, and very satisfying. Being unable to pull of headshots on multiple targets with ease results in a far more measured and tense experience. Golden Eye with a mouse would have been god awful, and forgotten immediately.
Unless the enemy are moving pretty fast, mouse control can often result in making a game too easy - Halo being a good example. Superb on the Xbox, yet very average on the pc, and all because the perfect balance/challenge was destroyed by mouse control (no rumble and trigger buttons certainly detracted from the experience too)
And of course, analogue poos all over keyboard movement - especially in games that involve stealth.
Having said all this - I wouldn't give up online pc shooters for anything. For something a little more immersive and single player, i'll take a pad almost everytime.