To be honest, the r7 is actually better, but in this pricepoint with such low end cards, it doesnt really matter, you may lose 1 fps, maybe 5 at worst case if you go with the 750, who cares
Buy the one that you feel better and safer, its up to you to decide anyway
And just to know, some things are magnifyed both from amd and nvidia fanboys for the opponent cards, drivers are more important than the card itself, really?!?
And how many guys got a blackscreen,and how often?
And have you ever heard that amd cpus consume more power,actually between 125watt(i5-some i7) and 220 watt(fx 9xxx) you pay the enormous amount of 25-30$ more per year, if the pc is under full load about 4 hours a day(imposible?)?
Same goes for intel and nvidia, dont think that amd is better because of this examples, just escape the fanboysm and make fair comparisons