Really, your odds of getting a bad card is still very slim with any brand. Yeah some companies have worse quality control than others but nothing is going to be really bad. I have a sparkle 2g 560 that still works like a champ I used it for 1.5 years and now is in my little brothers build.
Now after saying that, it was part of a prebuilt. I'm pretty sure I wouldn't have purchased it when building, unless some crazy deal like your 770.
I had a PNY card a couple of years ago, I cant remember what card though. It ran hot and after 3 months the fan on it went out and the card overheated and fried. Got a replacement and right after the warranty ran out the same thing happened, fan went out and the card overheated.