Sex is such a wonderful part of life. I could not continue my marriage without it.
There may be wonderful things about your wife aside from sex that you enjoy and appreciate, but I guarantee you that another woman exists with the same attributes, but who *also* enjoys sex. So in that context, if living a sexless life is making you miserable, it seems the only right decision is to move on.
Sounds good. Open marriage is better than cheating, and like you said many people who "cheat" won't even have the decency to at least open it up and make it fair. Perhaps another sexual partner could respark your wifes sexuality as well. But for now, I think you've waited long enough for a sex life, and you love your time with your wife, you should determine the best manner in which you want to open it up for you to have a sex life. It's possible with the right arrangement both of you will be happier than you've been in years.
Sure, and that's what a lot of people do. And if I may make a lighthearted poke at your wording, to me my wife is more than just a package of attributes. So much so that I already know that even if I were to have a new wife who LOVED sex, I would be sad and wondering what I gave up if we were to say, visit some of the same vacation places I've been with my wife and the mother of my children.
It's a sort of situation that has made me appreciate why some people go for open marriage. I find it somewhat ironic that people who criticize open marriages have often had, or are currently having, affairs of their own, which are essentially "inferior" open marriages in the sense that they are dishonest instead of open and honest.