I bought a mouse/keyboard adapter because it was the most familiar and comfortable way for me to play. You have to suffer because of your console leanings? Why should I be prohibited from owning and enjoying an Xbox, just because I can't play with a joypad? I'm all thumbs with a joypad on FPS's. I need a M/K option just to contend.
Since playing with the M/K option, I can hold my own.... but there are PLENTY of HALO 2 players that carve my keister off in HALO 2..... using a regular controller. If you practice, and you get GREAT with a controller, you've got nothing to worry about.