I purchased a MSI 560 ti (stock speeds, actually have a post here asking about getting the 950 clocked one... though I can over clock the stock one to that just fine without a volt change, so who knows).
Every game I've run at it, from Sims 3 to Metro 2033 it chews through with no problem.
I have Crysis 2 max settings (except AA), DX 11, 1920x1080, High res textures, and it plays very well (45-60 almost all the time). The only time I've seen a slow down is during extreme tesselation scenes... Such as a ton of water movement (see Lost Planet 2 benchmark test b at the end). The lowest I've seen is 15fps.
Metro it plays 30+ (usually 45+) all the time as well everything also on max except AA.
Overall I'm very pleased with it. If anything that will give you at least a reference. Personally I feel its great performance at a great price. I once spent almost $2000 on some video cards (2 xfx 8800 ultras and custom coolers) and they are still rocking, but for the difference in performance I felt it was a little overkill. Heck my 9800 gts in this laptop still rocks crysis 1 on max 1920x1080 at decent FPS because of optimization.
Thats just something to think about, price per FPS and future optimization of drivers and software.