Sorry Burg they don't respect anyone's thread... But anyways doesn't matter what anyone tells you, because in the long run you are gona try both and make a decision on what you like.
imo, Petrols if you're a rgoue, BoA's if anything else for example a feral druid, but like priesto said, try them both and just go with which ones you like/prefer
Just a heads up, but I saw petrolspills on horde ah on Outland. I'd have bought them but I don't have any mains on that server with gold... Think they were on at 2500 which I thought was a pretty fair price