To Stoofa and anybody else with a new Samsung box that is interested.
I received my Seagate ST3500830SCE 500GB drive today. I transferred all HD recordings and Anytime over using Copy+ and its now installed and running silently without a hitch.

The drive has exactly the same power consumption specs as its smaller 300GB brother so I didn't expect any. The only small issue is that there are not that many of these drives about now being last years 'vintage'.
Overall though I'm happy with the result and glad I went for this drive.