The thing with the 280x - 3 weeks ago I would have agrees wholeheartedly.
Then I did a build for someone who insisted on a 960 against my advice.
After building & testing - I've personally seen it outperform a 280x in the same rig on both witcher 3 & GTA V while pulling less than 300w from the wall socket.
Is it a better card in theory ? -no
Does it perform better on most current titles - yes because 90% of them are blatantly nvidia biased.
The 960 is plenty for that res,if I were going amd I would probably go for a 380 just for the fact its $30 cheaper & performs about the same as the 280x
http://pcpartpicker.com/part/msi-video-card-r93802gd5toc