Size has little to do w/ things. Majority of the nerves are in the first 2 inches. About the length of fingers. Thickness, well I'm not real sure it matters. I suppose it could be an issue for some, but not for others. It is like ice cream. It's all good, but which is better a small scoop or a medium scoop. It's all yummy, and how big of a scoop depends on the mood and person. Just like the penis preference. It is up to the individual, but it is all good.