After 10 years with E*, I had enough. Today the installers come and install my new service with D*. I'm getting the Plus HD DVR package and added the xtra HD channels, so other than the movie channels, I should get all the HD channels. The installer is also bringing the AM21 OTA turner to go with the HR21. I'm wanting to add the external drive, a large one. I'm currently using a WD Mybook 500 gig with the VIP622, but uses USB. Does the HR21 support this drive? Of not, what would be the best compatible drive to get?