I like the pad, and I used to be avidly against them. I remember when Halo came out, I wouldn't even give it the time of day. 'It uses a pad'. I did play it for a bit, completed it over coop even. It was ok, but no match for PC gaming. Could have partly been the TV though, composite on a 15yr old 20" colour TV...
Anyway, I've played FPS games on and off on consoles for the last 4 years or so. PCs always were significantly better and more fun, imho of course. The Xbox 360 has changed my mind, possibly because of HD and the wireless pads. They're more comfortable too. I find it much more immersive to hold a pad in a comfortable position playing a game than having one hand on the mouse, one hand on the keyboard, staring intently at the monitor.
Keyboard + Mouse combo is better for competition, no question. But at what cost? When playing MP on a console where everyone uses the same input its much more tactical. You can't do a 180 straight away, you can't survey your surroundings as easily. You tend to keep your back to the wall, you can actually dodge bullets from a less experienced player, and the amount of cheating is significantly reduced to the point that it doesn't matter.
I prefer gaming on a console, I'm a convert. I used to spend ludicrous amounts of money on my PC each year. Now I don't need to worry about driver settings, anti-piracy, new drivers, DirectX, OpenGL, new hardware, profiles, etc. Its just plug 'n' play in the purest way. The pad is fine when playing an FPS once you get used to it - and yes, even though I thought it was impossible even recently, it is actually possible to play an FPS on the hardest setting with a pad. It just requires more tactical thinking and good aim with the pad.