I have one and love it.
We use it for bigger tools. Seems about bullet proof. Had it a few years.
Easy to get and change fuses, though I never needed to. Easy and cheap to make a remote switch.
I don't think mine is very old. Thought it was originally bought for Y2K.
When I bought mine, they were still listed at some suppliers for around $450!
Probably not the highest efficiency, but perfect for my high power occasional loads.
Looks like it could use the cover removed and the dust blown out.
G-