The funny thing about those is that they were kind of deadly for their operators, and they couldn't do much due to the tyranny of physics. Johnny Quest loved to use something similar, however.
I can't see how...they seem extremely stable.
Just imagine you were leading the armored fist of a forty kilometer long Soviet convoy of heavy armor and expecting no resistance as you pour through the Fulda Gap. Then suddenly you're ambushed by a platoon of elite US Army Hover Troopers firing M1 Carbines down at you while buzzing about uncontrollably in the skies above. The psychological effect alone would be paralyzing.