The 7950 is more than 250$, it's better than the 660 gtx non ti, it's about the same performance as the 660 ti, if you can afford a 7950, why not the 660 ti ?
Since you had a previous nvidia card, you might want the 660 ti.
But if you want the 7950, by all means, it has two free games, if it's why you're looking it for, the two games being crysis 3 and bioshock infinite.
what resolution are you gaming at?
and what games?
btw, you might as well spend $20 more and get two free games as said before . .
1366×768 for games like sim city (new) and other upcoming games Im not to intense on my gaming just want the job done. I will get the twin frozr model w/ games since i really trust msi and my 560 is a twin frozr as well. One more thing Is a 650watt psu enough for this?
Yes, a decent psu with 650W is more than enough for it.
But if the maximum resolution of your monitor is just 1366×768, it's an overkill, in my opinion the 560 is really capable at that resolution, it can play any game at high settings at 720p.
And for sim city it will do.
But it's your money.