The R9 270X is on pair with a GTX 760, therefore it's performance will be better than the GTX 750 Ti. Although there is some points to take:
- The GTX 750 Ti is built with new Maxwell technology, which means it will consume less energy than the R9 270X
- The GTX 750 Ti should produce less heat than the R9 270X
- As far as has being shown, he GTX 750 Ti does not support SLI, so if you plan on running multiple graphics cards in the future, the 750 is not the way to go.
I personally am liking the performance of my GTX 760, I dont know the price for it in Australia, here in Brazil the differente is like $70~80 (The R9 270X for 910~930, and the GX 760 for 980~1k)