After a few issues with heat problems (I had the drive inside my A/V cabinet) the system is working fine. It's great to have so much available recording time. I think it's hardly worth the effort to add 500GB, or for that matter, 750GB when 1TB only costs a little more.
One question: If, at some point I have to replace the HR20, can the esata HDD be used with another DVR (I know I won't be able to access the programs from the previous DVR)? Do I have to do any thing after making such a change, or is it a simple "plug and play"?