Is Powercolor a reliable GPU brand?
Depends on the specific GPU.
Well, it will have a two year warranty from powercolor: http://www.powercolor.com/us/support_warranty.asp
I've used one powercolor GPU previously and it was fine. I cannot find any specific reviews focusing on the reliability of the particular GPU though.
powercolor is a great manufacturer. They build at the same level as HIS and Sapphire. They've been the official maker of the manufacturer for the 7990. They're in a way in house tuners because of their contracts together.