Whats the benefit of having 8 cores over 6?
Are they true 8 cores?
Looking into it, most people generally believe anything 4 core+ will do you fine. I often see people debate about if certain games and applications can really utilize more than 4 cores, if higher frequency and lesser cores is a better option, etc etc.
Apparently many AMD 6 core processors are slower than Intel quad core. I can't confirm this but I've read it time and time again.
The benefit to 8? Perhaps 'future proofing' and giving yourself more room to grow if you ever need it. Is it vital you get a true 8 core processor? Probably not.