Haha, don't get confused I might be the only dumb noob who uses a controller. I don't agree with statements that one is better than the other in generalizations, because the best Halo 2/Halo 3 player would absolutely put a highly accurate PC gamer to shame on said game. While ET was created for PC(and PC players will dominate), and has been a keyboard and mouse game since day one, that doesn't mean you can't use a controller and be good to okay.
A LOT OF PEOPLE joke about using a controller on ET, I think maybe less than 2% use a controller. I do because at first it was the best way to do it with the laptop--without a plug-in mouse. Some people still don't believe me when I say to them that I do, but that's because they suck and I'm terrible. (Marginally better )
But I use a controller and I am better than 50% of people.
Now huge drawbacks are, aiming at long range is almost impossible. Sometimes switching to correct gun/function isn't exactly great.
BUT there are great positives too, I can jump and aim better than PC players, I can aim better at CQB, but I can't vsay as well =/
I have one of the highest accuracies on J2 server's generally/headshots.
TL;DR
Controller is good if you are born and bred and willing to accept downfalls, but keyboard mouse is a equal if not always dominant better configuration.
PS
This is only fair if the one ET controller player get's a say.