Vacuum advance information and myths

It is good info, but oversimplified. Setting up MVA takes time, but no special tools.
As RustRatRod, found out [ post #8 ], MVA didn't work on his combo because of the low 6" of idle vacuum. MVA will never work with vac that low. At least RRR recognised what the problem was & didn't criticise the MVA concept. About 8" is probably the lowest it will work with & that needs careful calibrating.
Another futile move is trying to get stock VA units to work on engines that have reduced vacuum due to bigger cams installed.