So... here's what I'm curious about. What was the reason for changing? Financial? Management features? User-requested features?
I'm one of those people who believe that "if it ain't broke, don't fix it" so I'm just curious what was "broke" on the old version that's been "fixed" with the new one. Comments from "officials" and "users" both are solicited...
Security and stability are the main reasons for the switch. vB is far, far better than UBB in those regards. Even the new 7.3 beta version of UBB is just sprucing up the window dressing rather than addressing those long-running problems, so a change seemed logical.
As an "official," I probably look at it differently than you, but fewer and less frequent crashes, and better protection against trolls and duals is worth the loss of the "view all" function and whatever else we lost. (And we're not happy about the poll thing either. Hopefully there's a way we can change that, but right now we're more concerned with making sure it all runs correctly.)