I have one from MSI, and i can tell you it is very good, great for gaming at 1080p, also a cheap solution if you wan't to go for SLI in the future, the 560 ti SLI scaling is very good someting like "560 ti + 560 ti = 585" that is what they call lol...
If you are an amd fan you can also go for 6950 (normally used to comparisons agains 560 ti), great card also.
well nowdays you have the option to go for a 560 ti 448 core what is really good, better performance than a 570 but the price is also higher.
For the price, and the performance, i am really enjoying the 560 ti, and i know that when i need more firepower, i can go for sli buying another.