From all the reviews I've read/seen over the past couple months which is a lot... most people seem to like the Sapphire Tri-X best (although I think it's rather ugly looking, but whatever).
Nice to see the MSI actually put a backplate on their 290X Lightning. I was disappointed to see MSI didn't bother with that on their GTX 970. IMO, all $300 cards should have a backplate and I won't buy one that doesn't.
The only 290X card I've heard terrible reviews on is... ASUS. Which I hated to hear because I'm a loyal ASUS owner, but there's a bunch of reviews from certain Techies I highly respect who say ASUS did something terribly wrong with their cooler on that card. All 290x's get hot, but they say ASUS's version is the biggest toaster oven of all.