I recently upgraded from a 6300 to 8320, i'd have to say for gaming i don't see any difference so far (actually a net loss because i couldn't overclock the 8320 as high as my 6300). But it did speed up transcodes and renders quite a bit, so i'm happy with it. I wouldn't say it's worth the extra for a gaming only rig (and for anyone who doesn't do a lot of media work). a 6350 would be a good balance.
The 8320 would be more 'future proof'...if there is such a thing. But as others have already mentioned, the value/benefit you will get from it depends on what you want to use it for.
I would recommend getting a high quality AM3+ board that can support an FX 8350 or the next gen AMD CPU, but just get yourself an FX 6300 for now. 6350 isn't worth it IMHO since the 6300 can OC like a champ, easily reaching and surpassing 6350 clocks with a high quality cooler.
^ noob is correct. While i was able to get 4.0 on my M5a97 r2.0 without temps going up at all (i tried 4.2, but decided to stay at 4.0), my 8320 gets much too hot if i push past 3.7 or 3.8. At an attempted 4.0 OC it jumped up into the 70's stress testing and was headed on to the 80's if i hadn't stopped it. Stick with the 6300 if you are doing the M5A97 board,
Yeah i guess i will go with the asus board + 6300 since i am going to push the cpu to the limits and it seems that this wont be possible with the 8320 + the asus board. How far do you guys think that i could push the 6300 ?