Runco: "...The difference is guys with smaller penises tend to work harder to learn how to please women. .."
If a woman tells me she cannot feel my penis during intercourse, I'm not sure that "working harder" is going to help much. Of course I can use my tongue and my hands but most girls seem to want the thrill of penetration by something substantial. Girls have often complimented me on my "technique"--and then moved on to another guy who could give them what I can't.
Well you know that I think girth is important so I know where you are coming from but there are two things I would say to you. First, there are things you can do that will go a long way towards making up for not having the girth. I can't find it now but on Red Tube (I think) there is a 10-minute instructional video by a woman on the art of going down on a woman. The interesting part is her instruction on how to make a woman feel like she is being filled by a substantial penis through the use of your fingers. I would tend to think if you can use your penis in a similar way, you might be able to overcome some of this absence of girth.
The second thing is if you don't know where it is, locate the G-spot and learn how to work it for maximum enjoyment. Again, the video goes into some detail about the vagina - ALL the sensitive spots and how to touch them, stroke them, etc.
Yes, we do like to be filled but looking at this woman's video, I think you might be able to do a lot to retain interest. Also, I don't wish to be rude, but have you thought about a surgical solution, like fat transfer?