Paul:
I think it depends on your own personality and how fussy you are about the equipment you sail and fly. If you are really obsessive about the condition of the equipment, it drives you crazy to get to the boat and see it covered with seagull dung or get to the glider and know it really needs that weekend hard wax job or the trailer cleaned. If that stuff doesn't bother you, you can do both sports fine. I had 2 partners in my Beneteau F235 and owned a N3 sailplane at the time. I enjoyed both. But when my partners wanted out of the sailboat I gave it up. I just wasn't taking care of the boat the way I wanted to. But if I found a boat partner - I'd do it again.
ROY