Meh, I wouldn't pick either. I'd get a tube mech because there is such a larger variety of mechs and drippers that look beautiful together, and 8 drops every 45 minutes is a ritual that is not a bother. In fact, I kind of enjoy it.
But if I had to pick, I'd choose a reo because it can fire at lower ohms than the provari. It however, is not a true mech and can't fire at any ohms.