If the price for both those cards are the same, that your PSU is made by a reputable brand, is reliably built and has 650W of power at the entire system's disposal, then I'd pick XFX card. The cooling on it is looks better designed than the MSI.
I would put it under brand preference or price difference since they are equal in clock and memory speeds. I do have and have had GPU's from both brands with out any issue.
XFX is the way to go. This round of AMD cards they stepped up their game in build quality that plagued the 580/570 series that was sorta fixed in the 5700 series