I wanted one of these for three reasons:
1. I wanted to supply power to the units in my rack case without a tangle of cables or .
2. I wanted to minimise/eliminate any mains noise and hum.
3. It looks cool and professional.
If you want to power multiple valve power amps, you'll need something higher up the range, but if you've ever played in a club with crappy, buzzy mains power, these are great.
Mine powers my AxeFX III, Helix Rack and a Scarlett 18i20 with just one power cable to the case. The switch on the case means I can turn everything on and off easily. Fewer cables running back and forth makes things safer, neater and (arguably) sound better. There's even a socket on the front if you need one.
There are models with added lights, bells and whistles, but if you don't need the extras, this does just fine.