I haven't tried play-by-Wave yet, but was involved in a number of play-by-e-mail games back in the day. I'd say PBeM can be just as fun as face-to-face, it's just a slightly different kind of fun. It's less of a social event, and there's less instant gratification. But a well-done PBeM can be very rich in a way that's hard to do face-to-face. You don't get that instant rush of gaming (very often, anyway) but you do get much more time to think about what you are doing and saying, which can be really helpful for the "role" part of role-playing.