Not sure if you already made this decision... however this is the situation i was in too. i bought the 750 ti before the 960 came out (at least i thought it wasnt out at the time).
i only have a 460w PSU (dell) and dont want to deal with upgrading it (i know alot of people wouldnt like that), so i was limited to my gpu choice. the 750 ti only runs warcraft at medium with 60 fps constant, from benchmarks ive seen, the 960 will run it at ultra ith 60 fps. Plus i sold my 750 ti on ebay for 100 bucks and i only paid 100 😀