Expected life of a MC amp

I have a Rotel RMB-1075 purchased preowned here on Gon about two years ago (120W/Ch continuous, 5 channels). The unit is probably 6 years old and is working perfectly. Original owner took excellent care of it. Just curious how long a unit like this would last and what can I do to maximize its life? I don't do anything to it but use it. I do turn it on via a 12V trigger from my AVR/Pre. What do you all think an expected life of this unit would be? I use it probably 5 times per week for several hours at a clip and do crank up the volume !! Thanks.
If you are using it that much I'd probably just leave SS on vs. turning it on/off 5 times/week (260 times/yr.). Probably sound a bit better too.
Thanks folks. Appreciate the feedback. Good stuff.

Is there anyway to know if the amp is actually putting out its rated amps? Do you think over time as it gets older its output begins to diminish?