The difference is remarkable. I was earning ~$1-2 p/day with AdBrite, my first day with Google AdSense earnt me $10. I should have switched a long time ago.
What kind of traffic do you get? I heard that sites with large traffic make a higher CPM than low traffic sites when it comes to adbrite. Trying to figure out if its true or not.
nigeps just make sure you read their terms inside and out and make sure no one screws you over by clicking your ads too many times. i like to give people a chance and adsense completely screwed me over. wasn't for a lot of money, but shut my account down and all I did was show them on my site. nothing on their terms I read that pointed to something I did, but gone. good luck to you.