Hi Johnathan,
I put my M500s into standby mode (pulsing red logo, very cool!) when I am not listening to them.
What are the M500s doing what the 2W they consume?
Is t there just to keep the capacitors charged up to prevent any inrush of current when they are turned back on?
The top of the case is very, slightly warm to the touch. Is keeping the internal components warm to minimize thermal cycling?
Just curious,
Dan
Dan,
The standby mode essentially disconnects the outputs to the speakers and leave the amplifiers on. In case of a power spike the speakers will be protected.
The amplifier stays on and keeps all of the silicon devices warm. They perform optimally at a specific temperature, which can take 24 hours to achieve from a cold start. You can let your ear decide if the power to keep the amp warm all the time is worth it 
I typically keep my system on unless I will be out of town for a day or two. Compared to other power appliances, it is pretty minimal consumption!
Hope that helps.
Thanks, that’s useful info.
Dan