Hey all, its been a while since I posted in the GPU section and I couldn't find anything that satisfied my questions so I'll ask in this tread.   I've had a 5870 for the past 3 years and have decided its time to upgrade (yay!!!) and gonna go back to the Nvidia side of things.  So, I need a few opinions and if you have any graphs or data to share that would be great as opinions are baseless unless you can back it up.   I'm looking at either a 680 or 670.  My current display is 2560x1440 so its gonna need some horsepower to push skyrim and BF3 at that res, though my 5870 could play it, just not maxed. 
 
1.)  Do I even need to worry about 4GB versions?  My gut feeling is "no" but I'm not sure. 
2.)  Are the bugs for the 670s fixed? 
3.)  What card is better for gaming at the resolution?
4.) My budget is $500 and cheaper is better unless the higher priced cards are worth the cash.  Which card is the best price/performance ratio? 
5.)  What card overclocks better?  (obviously it depends on each card, but in general do 670s or 680s get better mild overclocks?)
 
 
Those are a few of my questions, what should I do?