Yes, it uses an external laptop-style power supply.
The gauge is non-functional. Just looks cool. I like how the copper tone offsets the black.
It sounds good. All of the TPA3116 and 3110 amps I've heard are really good, and excellent considering the price.
My speakers are DIY OB, so not "audiophile".

I did have the Steampunk amp playing for a couple of months on the Pioneer '41 bookshelves, and that was a good combo too.