Another vote for going longer, at least to see what you're comfortable with. It's only by trying things you figure out what you want. And also one thing to consider is that you don't have to have even growth/length all over. I'm still growing out my chin and lower cheeks, but my upper cheeks and neck I keep trimmed. So it's not an all or nothing endeavor. In any event, the beard looks really nice as is--I think it defines your face quite well, and is well-proportioned--but if you're at all curious how added length might look and feel, you owe it to yourself at least to try it out.