GTX970 or R9 390 for running Dolphin?

[AnyOldName3]

If I was in your situation right now, I'd get the 390, but not for reasons of performance (they're extremely similar at 1080p, with the 390 winning slightly at higher resolutions). The reason would be that nVidia have been pretty anti-consumer (e.g. 3.5-gate) and anti-competitive (e.g. GameWorks) recently, so I'd feel my money would end up doing more good in AMD's hands than nVidia's.