I'm a developer and I dislike Google Groups. Do you know any normal people who use it? I haven't looked at Breeze but assume it would be worth $10 to most people who require that functionality.
I don't know how they can blatantly lie and tell buyers that they're better off with their $10/month service over the free Google Groups, but they seem to be getting away with it. Because they're 37 Signals and everything else they make is amazing.