I think having a penis not only makes masturbation better...but almost necessary, since I'm not quite sure how a guy could spank it without one.
My penis has given me great fulfillment throughout my life in regards to sex. Indeed, we have been through good times and hard times (no pun intended

) together.
Size has nothing to do with amount of fulfillment; although I understand there might be a certain penile-centric website out there whose members might think otherwise

.
Although a great part of life, but yes I do think sex is overrated in society; although porn, Madison Avenue and again, a certain website might try to convince you otherwise.
There are plenty of other things a man should focus on to bring them happiness besides their dangly bits. Although self actualization may be one of the most difficult things one can achieve, I'm almost assured no guy will ever reach it by the simple act of possessing a penis.
As important as my penis might have been to my wife (or any other women I've been with for that matter), nothing can replace the more important emotional aspect. If anything, at this point in our life and marriage, emotional connection and our relationship is more core to any continued happiness than my penis or even sex in general. I'd rather choose to not have the use of said penis and still have our emotional connection intact then the reverse.