Should Class A Amps be left on??

Ok- Audiogon members need some advice here. Should Solid State Class A Amps be powered all the time? Have heard two school of thoughts on this. Apparently from what I have heard this is a moot question for Class A/B amps due to the usual low biasing of A/B Amps. From what I have been to learn so far Class A Amps should be left continously on.
@unsound : you are correct! A true Class A amp (like a Bedini 25/25) will get quite hot by 30 minutes after turn-on. Playing music for an hour will then lower its temperature significantly as the speaker load absorbs current. That is the mark of a true Class A circuit! If the amp temperature remains hot it is going into Class B past a few watts of Class A power! How do I know this? I owned a Bedini 25/25 for 10+ years as my "daily driver"! The Sumo Nine mentioned here is Class A only for the first 15 watts! After that it goes to Class B for a maximum of 60 wpc! Audio magazine had a test report on it back in the 80's. True Class A amps are most efficient when they are driving a load/speaker.
My Sumo Andromeda (another James Bongiorno design like his Nine) is Class A for the first 15 watts. Then it goes to Class B for 200 wpc! It still sounds excellent at the higher power range - a mark of an excellent design! I turn it off at day's end! 
Pass Labs XA60.5 that I put in standby when not playing music. Yes, they did increase power consumption slightly, but with solar panels, I don’t have an electric bill so no problem. :-)
If your Class A amp doesn’t have a standby mode, turn it off over night. If it doesn’t sound good enough 30-60 minutes after powering on, or into Class A, get another amp.
Turn on 1 hour before listing only.