Only just got this game and I personally think it is absolutely amazing. I hardly have any lag issues compared to a certain game *cough* Black ops *cough* and everything seems to run smooth.
Only downside is MP is just like the campaign (so I have been told) and for that I can't wait for future DLC's (after this free one) as I will probably purchase them all as this game is worth the money.
To them guys who have issues sorry to hear that and hope the company fixes them for you so you can enjoy Brink the way it's meant to be played

So yer just wanted to say hi and share my experiences.
Happy gaming!