In terms of GAME PERFORMANCE (I cannot stress that enough, I do not care about the "on paper specs"), which DESKTOP GPU is the 680M similar to? I.E. the 680M gets the same FPS, graphics quality, etc. as the ___________ desktop model. Fill in the blank, PLEASE!
I play games such as Battlefield 3 and Far Cry 3....
Ive read its closer the a 670. Very few laptops have the 680m so If you can afford one with it, go for it. About the best it gets in a mobile GPU. My last laptop was a Asus G73sw and a 460m in 2011 which played Bf3 at medium to high settings at 1080p. I'm sure the 680m is vastly superior to that now.
The GTX 680m is less powerful than GTX 660 Ti. It will struggle with Far Cry 3 and Hitman: Absolution on 1920x1080 resolution with ultra settings. The same with Sleeping Dogs and Metro 2033. BF3 performance should okay / good enough, but not great.