It uses less power,but both of those cards run cool. Of course,the 750 Ti will run slightly cooler,but you don't really have to worry about the temps on either of these cards since they're not high end cards and they do not have high TDPs.
I'd go for the cheaper card (if you want to buy one). I'd recommend ASUS,Gigabyte,EVGA for the 750 Ti and the ASUS,Gigabyte,Sapphire for the 260X (if you want to buy one). That's just what I'd prefer to have in my PC,but if you want something else,then go for it (if you want to buy one). Also make sure you have a good PSU to go with the card (if you want to buy one). 😀