Read the article here...http://hardocp.com/article/2012/04/04/nvidia_kepler_geforce_gtx_680_overclocking_review/1
After reading you can draw the conclusion that's best for your useage...as for drivers...amd has a better track record of stable and fewer bugs than nvidia as of late...say the past 2-3 years and this provides for more play time and less "pull out all the hair" time.
The two cards are extremely close in the benchmarks and in most cases withing a few percentage points with one gaining a little and the other gaining a little there...the two video cards perform incredibly well so it's a personal preference thing and not really a performance thing.
I would read the article, decide which fits your gaming preferences better and then compare my budget to the actual costs...look at warranties and decide for yourself which you prefer or which card matches up best for you!!!!!
P.S. if power consumption is a thing ie...going green...that's in the article as well...remember less power....the lower the electric bill...the more green you are
Just a thought!
Respectfully,
tekman42