I still use one to test PSUs. See what happens on the meter when simulating a PC load (or in fact actually using it to run a loaded up junky old PC) and the voltage is varied. The manufacturer bragsheet is always fulla **** (or at least one needs to assume such is the case in a modern world filled with Shenzhen electronics), actual test bench data never lies or omits info of real importance. If I'm gonna upgrade a cluster or even spend some big bucks on a high end PSU for personal use I wanna ensure I get something worthy. My computers don't suffer brain damage from momentary voltage dips, drops, brownouts, surges, and spikes. Then again, I only use the autotransformer about twice per year, most of the time it's just a handy flat surface for holding screws and heatsinks.