1. Not really, and you never know who to blame. Because the developer blames AMD and AMD blames the developer. Crossfire for FC4 does not work, the game has been out for a while and had several patches. Still nothing. But then there are other games where an AMD GPU will actually perform better than an nVidia counterpart. You just have to suck it up before you commit to either side that sometimes games aren't going to work properly, no matter what type of card you own.
2. For AMD GPUs I look at (Sapphire, MSI, Gigabyte, ASUS) then if there's a killer deal (XFX, HIS, PowerColor, Visiontek). I used to love XFX cards but then the last few I bought had that aluminum or metal alloy shroud with the fans, and it always rattled, or it was always really hot out of the box. Then to change the paste you have to document a request with customer service before you break the seal, otherwise your warranty is void. They could have fixed some of this stuff in the past 2 years. But I've been buying mostly Sapphire and Gigabyte. I had a few Visiontek cards (7970 reference and R9 280X) and they worked great.
That said I would go for it, but since you're looking at cards in the $225 range it might be worth noting that R9 290 4GB cards with dual fan coolers are starting near that price now. I saw one the other day for $239.
If you're going to get a 280X, I wouldn't spend more than $200 on it.
EDIT:
Hmm it looks like the prices I quoted were temporary sale prices. I would wait for one of those deals again, Newegg Shellshocker or something of the like. The dual fan XFX 290 was reduced to $249.99 and then a rebate as well.
Right now the going rate on a 280X looks to be $250 which at the moment I don't think is a very good deal. Of course it really all depends on the resolution. If it's 1080p or less, get yourself a GTX 960 for $200. Performs equal or better to a 280X in most every game at 1080p.