> It greatly depends on usage (how often you record, how often you have  
> recording conflicts resolved by multiple backends, etc.) 

That really is the crux of the issue isn't it

> My master backend stays on all the time... 
> ...because I record  enough where it would probably only shut off a couple of times a day  
> for a short time. The wear and tear on constantly shutting down and  
> starting up makes it much less desirable.

Yes, I agree with you for your case. In my case the system rarely records anything during the day and can be recording up to 4 things at once in the evenings. What this means for me is that in contrast to you my backend is often recording for less time than the frontends are playing-back. Great example is if we watch recordings during the day on the weekend, if we weren't watching recordings the backend would almost never turn on. This is why I would be interested in shutting down the backend when I just want to watch what it has recorded (or what I have downloaded).

PS: What country are you from? Australia have bugger all on during the day at the moment; crappy dramas, c-grade movies, judge judy/joe brown/other clones and repeats of shows like Just Shoot Me or Seinfeld (this might change with the extra digital channels but I'm not holding my breath).