A quick browse through the fansite of any unconventional-looking celebrity, or the darker parts of anyone's porno habits will tell you that human beings have a wide range of things they find attractive.
Treating women like the latest apple product that you can rank and then show off to your friends as a trophy of how cool you are... that's gonna get you rejected every time. Women aren't stupid and can tell when you don't actually like who they are as a person.
Also "average penis" really isn't an indicator about anything. Being good at sex is about paying attention to your partner, as well as having hand skills, mouth skills, and the core strength and general coordination to fuck well.