Love me a good mech (I have dozens of them in all shapes and sizes). I spent a good few months being schooled by the experts who used to frequent this forum and am entirely comfortable using them these days.
I wouldn't necessarily agree they are dangerous though but keep the myth going, keeps the wingnuts away.
Positives include being able to taste the subtle differences in some complex juices as the power drops and they never die unlike regulated mods which you know will die on you at some point.