(1) Powercolor has a lifetime warranty on retail cards vs 1 year on HIS, but HIS has a slightly better reputation for overclocking & also offers the IceQ cards with a factory-installed NV-Silencer type cooler.
(2) I'd stay away from any "open-box" video card, even from Newegg ... my guess is a lot of these are cards that didn't overclock to the buyers expectations & thats why they were returned.