Hmmm, I just RMA'd a 550 to the Egg because there was a part flopping around inside the PS housing. Haven't gotten the replacement yet. Damn, I hope the one I got is ok. Maybe I should go with the new Enermax Liberty, they look pretty sweet.
http://www.newegg.com/Product/Product.asp?Item=N82E16817194004
http://www.newegg.com/Product/Product.asp?Item=N82E16817194004