Just a quick note. Splash Damage has released a patch for Brink via Steam that addresses a lot of the issues people have been having with the Windows version of the game. I gave it a try last night and it has indeed made substantial improvements. There still seem to be a few little quirks and bugs for them to iron out; especially with regard to sound, but there's now no doubt that they're taking customer feedback about the game into consideration and acting on it in a timely manner. I'm now even more confident endorsing this game and encourage anyone who's interested in it to give it a try.
I should also mention that Splash Damage has announced that the first DLC for Brink, which is scheduled to be released in June, will be free as a "thank you" to everyone for buying the game and putting up with the initial technical problems. Perhaps that's just PR spin on their part, but free "maps and additional content" sounds good to me in any case. :)