Welcome. Man, you have a perfect beard and shouldn't waste it. It's your face and even wifes shouldn't rule over that. My tactic is to tell her often that I love her and just grow what I want, more or less ignoring any comments (which are not often). As your beard looks great at any length, I wouldn't reach out for something extreme though, but first stay within the range that is accepted as "stylish" by society. That makes it more easy for your wife to come around, especially when you will get compliments from others, what will be quite likely.  

- Successfully certified by myself. -