Since when has the Vulcan ever been called 'Brunty'?
As for the sedate display, well I believe the airframe is fatigue and G limited at present, and they're down to six usable engines at the moment as well, although the other two haven't been completely written off as yet.
I'm sure if there were an abundance of zero timed engines available we'd be having all the power climbs and noise we could take, sadly that's not the case and engine cycles have to be managed effectively.