Well I'm not exactly an early adopter of new technologies. I generally like to wait until bugs are worked out, and I've been holding off on the whole VOIP thing. But I would have to say that Vonage is starting to pull me. They have a serious technology offering, and you can't argue with the price savings.
Anyhow, the forum on the site linked above has got me feeling a whole lot more comfortable with the idea of switching. With over 34000 users on the forum, and a dedicated forum for Vonage Canada, I'm pretty any issues I'd have would be remedied much more quickly with the help of a community.