Voltage Regulator

Just my opinion.

If I was having that many problems with any voltage regulator I would be checking the rotor to see if it was pulling excessive amps.

Maybe new aftermarket VRs are all crap, but unless that are made of the most under rated parts (the companies having them made are responsible NOT the manufacturer) then there is something else causing the failure.

An intermitant short in the rotors winding?
An intermitant short in the underhood wiring?
User error?