No, I think you can get a decent sound at home. The character and feel of tubes amps change as they get louder, but modern tube amps like the Satan are built with good master volumes and features to help you dial in the tone. Amps these days have resonance, presence, tight, bright, and all kinds of other settings. These are often useful for dialing in good low volume sounds. Typically, but surely not always, amps with a resonance control at low volumes keep a tighter low end when you dial the bass back and turn the resonance up, but the opposite is true as it get louder. Some amps, like Engl and some Mesa Boogies get brighter as you increase the volume and gain. On some amps, the controls are pretty straightforward. They either add or take away something. On other amps, when you turn one control up or down, it affects the other controls.
Having said all of that, yeah, I've played it at low volume just fine. Check out the Diezel Herbert. I think it's like 150 watts, but the owners swear that it's the best sounding at low volumes than any other Diezel. Go figure.
One last thing, just because an amp is lower wattage doesn't mean it sounds better at low volume. In fact, many times it's the opposite. Because they're built with smaller tubes, transformers, etc. they rely on volume to get all the goods. The big iron amps with 4 power tubes often sound better at home volumes.
Pedals also have a lot to do with it. You can push an amp with a pedal and still turn down the volume using the pedal which allows you to turn the amp up without being louder. That sometimes works. Some amps let you jumper the FX loop loop and use it like a 2nd master volume. You can turn the amp up where the tubes get hotter, but use the FX level to keep the volume low.
There are a lot of ways to get a good low volume sound out of big amps. Don't think as a general rule that low volume amps are better for home because I find that to less likely be true. Check out Blackstar amps. They have one of the most incredible power reduction features of any amp. You can get some brutal tones at quiet volume.
