Gain and level controls on an amplifier-a good thing?

@jl35 Not really surprised.  For most of us, those level controls are just one more component for the signal to go through.

I think there is nothing wrong with having a volume control, as long the circuit is properly designed. My power amp has one and the manufacturer said some people prefer to not use a preamp, so they are glad to have it. His design is such that if you use a preamp, as I do, and wish to eliminate the amp volume control, to turn it all the way up. This effectively removes it from the circuit. I can verify this as there is a noticeable difference in sound if I don't turn it up fully, it is then obviously engaged. Even though I don't normally utilize the volume control, I am glad to have it as there are some recordings which sound better when I do use it.

Handy if you have very hi efficiency speakers and the ability to dump gain from a preamp can be useful. other than similar reasons it just adds another volume pot to the chain. 

Should have been more clear.  Installers love them because it gives them the chance to balance speakers in different rooms, so this is really, IMHO more of a whole home audio kind of feature than it is something the average audiophile would use.

Good if you have a use case.

Not good otherwise.