I think it's possible to edit a great set of
questions that have VVBs, and indeed to to have a set of
about average quality where many teams decide they'd
rather get the (relatively easy) 20-point bonuses than
the (relatively difficult) 30-point bonuses.
HOWEVER...
If my team is 35 points down entering what looks
like the final tossup, in a situation where many of
the bonuses are worth up to 30 points, then the idea
that we could nail the tossup and yet be doomed with a
20-point bonus would seem grossly unfair.
Whether
that actually is unfair or not, the perception is so
problematic that I predict that VVB's will remain passe for a
long time.
Matt