The TU-HP01 actually a pretty awesome intro to tube amps without spending too much (They're approx $200 in Japan based on current exchange rates). It's more susceptible to vibrations in comparison to the larger tube amps. I'm actually quite surprised a low cost kit amp like this sounds the way it does. Granted it's a hybrid and I did plonk in a $40 Muses02 OpAmp in it but this tube amp is like a gem in a garage sale.
Believe it or not, I do bring it to the office or to the local cafe. Basically anywhere I can sit down for at least an hour or two, I'd bring it out. Naturally if I'm going shopping, taking the train, bus, or walking around I don't use it. It actually doesn't produce much heat at all. Even after an hour's worth of operation, I can touch the tubes. The glow is actually from LED.