This is a rather late contribution but I only just heard about the thread, hopefully I haven't arrived after everyone has left the party. I'm one of the people that uses a VRIAB - but only at the end of aerobatic lessons and only when I can identify circuit traffic and fit in safely.
At my base airfield the VRIAB is restricted to aerobatic instructors, flown sensibly it is fun and safe but the military R/T and technique needs to be modified slightly ("high/long finals/base to break" rather than "initials") so that others know what's going on.
Aerobatic tuition is mostly done above 3000ft and nearish (but not too near) to the airfield so at the end of the lesson there is significant height to lose. The most efficient way of doing this is to set enough power to keep the engine warm (18-21") and descend continuously to a VRIAB. Approaching the airfield we get the airfield info and an idea of the number in the circuit, if appropriate we then call "run and break in x minutes". Positioning just to the dead side of the runway and, when close to the airfield, descending to below circuit height (to enhance visibility of circuit traffic) and then run down the airfield to a climbing break at an appropriate point and either descending curved approach to land or extend and join behind someone else - again, as appropriate.
Safe, efficient, good for the engine and saves the stude a bit of money. It is not a "beat up".
There are pitfalls if Bloggs tries it because of the low level accelerated stall risk but when flown sensibly and professionally I really don't believe there's a problem. A useful technique when appropriate UNLIKE STRAIGHT-IN APPROACHES
which I believe are dangerous at non-ATC fields and SHOULD be replaced by a level version of the VRIAB onto the crosswind leg or an overhead join.
BTW someone suggested a while back in this thread that people performing aerobatics should tell someone - unfortunately there's usually nobody worth telling so a 7004 squawk is all we can do.
(apologies for the bad grammar, typed in a hurry)