This may just be pointing out the obvious, but small differences in girth make a huge difference sexually wise. For example a 6 inch girth will feel much bigger than 5 inch girth, and 7 inch girth will feel much thicker than 6 inch girth. This goes for both oral and vaginal - anal too for that matter. This is just speculation of course but judging from my own sexual experiences and what I see in porn. A 6inch-ish girth will be fine for most women but a 7 inch like Shane Diesel will require slow movements and will illicit never before seen facial gestures from the receiving party. I just think it's amazing 1 inch makes such a difference.