My ex-husband had 10+ inches and sent me to the hospital for severe cervical bruising on several occasions (BTW: THANKS, PAUL!!!).
Having one that big is a great big HELL NO to any oral or anal... talk about lockjaw... that's PROBABLY why I have problems with arthritis in my jaw! (TMJ Syndrome)
In regards to size... I'll stick with the 7 that Larren has! It suits me fine, and sometimes, if he's got feet on the wall or footboard, I get hurt anyway... so heck. I'll stay away from those 8s!!!