Because off psaix if the price is good?
Not sure what psaix is a acronym for, though IDK the $140 isn't earthshattering, seems pricey this late in the game.
You could've grab a Asus STRIX R7 370 Overclocked 2Gb (1050Mhz) for $120 @ MicroCenter for monthes; though last I check it was OoS.
I'd like the two of them go one-on-one, in a lower end OEM box. I don't think there any dramatic difference in game-play immersive-ness when you make nice playable settings for the 950 then run a 370 at those same settings. As to power (odd no 370 numbers though a 270X (5% more power, while the gameplay is on a 370) I think the days of running one game pulling a number and calling it "the average" is no longer acceptable or persuasive.
If you test multiple titles you see how power usage fluctuates. Here you'll see what Jarred Walton from what was formally MaximumPC now PCGamer found in his test of an EVGA 960 2GB SSC GAMING and a Sapphire 380 Nitro 4Gb. His findings substantiate the point of how a boosted card(s) draw power differently given the titles and their work loads.
http://www.pcgamer.com/sapphire-radeon-r9-380-4gb-review/
While it's nice that a card can offer this level performance from PCI-E power, would I limit myself to a non-6 Pin purchase... not unless there are specific criteria the machine or a build had targeting. If your has Molex or SATA connectors unused your PSU is most likely not going to baulk on a 370 unless less than say 320W.
