You would need to have a big package that you can make bigger and smaller to really find out what changes with pecker size. My experiences on top of my head with 16 girls:
I have yet to find a girl that did not cum before and then erupts when I bang her with a really fat pecker (extension).
Some girls just cum like crazy, even from just banging them with my small package. Seldom ones just don't bust a nut at all. Some only with a superstrong vibrator. Some just come clitorally. One girl (ugly fat girl btw) i know really needs a big dong to explode, she screens for that.
When watching porn it's the same I feel: some girls come like crazy - it seems like because of the big dong, cause they all got a big dong and the females also of course act like being cock-crazed about it. Others get the biggest schlongs inserted into them and i am thinking 'my fb screams so much more'. Learn more about X4 labs at http://astrobiosociety.org/x4-labs-device-review/ and https://erinjgz.wordpress.com/2016/03/28/phallacy-for-men-and-extenders/
I am about the 6" of girth mentioned. While I can confirm that women think a lot about size, and that girth is far more important than length, I would still say, that size never allowed me to do, what I can do today with the experience I have. The comparison is not even close. As usual asking women what they want in men is fraught with problems, the chief one being their will to be honest, and their own experience. What I can do with my experience is apparently so rare that none of the women I have been with over the last couple of years, nor any of their friends have heard of anything like it, nor did they believe it was even possible. Many of the friends still won't believe it is real. I don't say this to shamelessly promote myself, or to impress you, but just to point out, that the answers you get with such a query depends on the people you ask, more than it depends on the actual truth.
Does the Bathmate or Sizegenetics work?
Size it’s not important, unless you really have a small pecker, like tiny small. Most people its just average. That's for women and men, average pussies swallowing average peckers.
And its also about the girl perception, cuz most don’t even have climaxes, so a big schlong is just a mental thing to some girls, like they really want to feel filled up, but I have also noticed that girls that are good in bed really grab my cock with their pussy, so its also a thing about them knowing what to do with a d*ck in their pussy.
And intercourse is an expression of who you are rather than just two organs friction, yes the mechanic aspect is important but really being in touch and really banging a girl is where is at, bioenergetics and reichian works teach that, the amount of satisfation you get from intercourse is something that reflects your whole body and the relaxation you and your girl have.