"How to live with a huge penis" is a good attempt about a serious subject, but I think that the authors were confused as to whether they wanted to go ahead with a funny book or a serious book and in the end messed the whole thing. It would have been much better if the authors were serious about a subject that is sensitive. I have a relative who suffers from oversized male genitalia, and I have seen him suffer from bouts of depression. His shrink always asks him to ignore the problem and be more confident. Well, it is easier said than done.
To sum up, I would say that the authors had a golden chance to address a silent problem that is plaguing many Americans, but they seem to have botched it up spectacularly.