Its no where on Par with the GTX 670 but it would be fine depending on what you going to use it for. Me? I do heavy gaming and I like to play my games like Battlefield 3 and MOHWF on the highest yet most comfortable settings. Don't expect to run 2013 games like Crysis 3, Far Cry 3, and Dead Space 3 on High Settings and full 1080p but you can sure run it on Mid settings at 720 with out having to compromise on FPS on the GTX 660 TI and still get 60 FPS. Bottom line the 660 Ti is a good card but not future proof, unless you plan on doing SLI, if you won't SLI then I would just invest the extra 50 or 70$ and get the GTX 670 which even though is bound to be outdated in the near future, it will hold the best value in the long run, In my opinion but I could be wrong according to someone else. If that is all you can invest for now, then yes by all means get it! You won't regret it. I came from the HD 5870 my self, which is similar to your HD 6870 when I built my new rig and now I have a single GTX 680 and I love it! You will see a big difference from what you have now. Just don't rush it, give it a few weeks and really take a look around at prices I got mine from eBay "NEW" for only $410, when at the time they retailed for almost $500
The 660 Ti is a very nice card. If you like NVIDIA and you want a card in that price range, really a 660 Ti is about your only option.
Go for it!
