Bugera PS1 Power Soak

Works pretty great but I would never hook up a 100 watt head to it. 65 watts would probably be the highest I would go.

As others have said, the more you attenuate the signal the more highs you lose but I have not noticed it to be all that bad personally. If there was any top end loss I made it up with the amp EQ easily.

I found the best aspect is that it can be used as a load box just note that if you do so you have to crank the big knob up to 0 (or no attenuation) and then the Line Level knob will begin to work. You can do this without a cab and it is fine.

Used this to DI a couple of amps I have into a cab IR in my DAW and sounded great.

Gets pretty warm after long use but nothing that will burn you.

Mine made a rather fishy smell (burn in) for the first day or two of heavy use. Stopped after that, just keep that in mind.

If you simply want to reduce the volume/output on a 15 watt and upwards valve amp without losing very much at all of the tonal quality, then this is an excellent product especially for the price...a great well built box...
But bear in mind two essential factors: firstly, the moment you put it between your amp and the speaker you are automatically reducing output by 50%; secondly, if you want to play or record silently using the emulated or line output (to a mixer/headphones for example) you can't do that without having sound still coming from the speaker, which has to take the load. No good for middle of the night recording unless you live alone in a castle!
If Bugera could get round these two factors it would be 5 star brilliant, but if you simply just want to 'tame' your valve amp to a much lower volume level then its a very good choice.

I wanted to start playing guitar again, and still have an old 100w tube head standing around. Considered buying a small low power head to use at home, but for less budget decided to try a power soak instead and continue to use the amp I already have.

Build quality is ok but it feels a bit light and cheaply put together. Does what it says, so soaks up power which allows a big amp to be used at in-house volumes. Can't really think of any other use case, unless someone bought the wrong amp. The fact that it's a passive unit makes it easy to use, it just sits between the head and speaker, however the lack of a headphone out does mean you still don't have an option for really silent practicing.

So yes it's a solution but basically only if you have the wrong amp at the wrong place and don't want to break the bank.