I don't know and my results are completely non-scientific, but I have been using a DirecTV DVR for more than 7 years. During that time I have had to replace my DVR 3 times (at my expense). I now have the DTV Genie which will also run 24/7 including while in-motion. I am hopeful that the option to sleep after 4 hours of inactivity will help extend the life of my DVR, but I am fully prepared to pay for a new one if necessary. I am a lazy so and so and I have my DVR setup so it never goes off (dedicated inverter) no matter what else happens.
