I’m not sure what the DirecTV DVR draws power-wise, but it is probably similar or even more than the Cable STB I had recently that was a receiver only. It drew about 20W all the time, even in standby. The DirecTV receiver will stay locked to the carriers even in standby so it is probably consuming something similar or more.
With your HTPC, you can let it sleep where it will only consume a couple watts so you may even be better off than you were with DTV in terms of power consumption.
