Well, I don't know this from personal experience, but my friend who is a Pinarello dealer told me within the last year that most people go to a smaller size in pinarello frames compared to others. (They run big). If I were you, I'd go with the 53 over the 54. I think you're generally better off with a smaller frame anyhow. You do enough riding that you deserve a better frame than that generic Chinese frame you were riding. Good choice, and get well soon both to you and your wife!