To be honest, the R9s aren't even that good anymore. I have a 7950/R9 280. A coworker recently was selling his GTX 970 recently and myself and another coworker were considering buying it. He built a low end system recently and bought a 560. With us looking online we decided the 970 was 96% faster than his card, and about 80+% faster than mine. Meaning my 7950, drawing ~200+W, was only 10-15% faster than his 560 which doesn't even draw 100W. Yes, mine is faster, but not in any meaningful way.
What I'm trying to say is that considering the frame rates and power draw, you are better off just getting the newest card you can. R9s are old, newer low end cards are just as good. I've considered what to do if my card dies and even low end cards like the 1050 or 1050TI are faster than the R9 280. And use less power. Which R9 is best for gaming/PUBG? None.