My 722 now has 3 750 GB WD drives connected through the 722-powered USB 4 port (~$6.50). I plug in the correct power supply to the end of a power strip, one at a time. My biggest complaint is that it takes a long time to transfer a number of files, especially painful when I changed my movie rating (IMDB) breakpoint from 8.0 to 8.1, BTW 8.0 is about 4 stars in normal parlance. You have to unload one disk and then load those files/recordings to the other and meanwhile you cannot watch any external recordings. It is helpful that restored recordings are flagged as protect--this prevents overwriting of those just restored. The third drive is for series like The War, Planet Earth, Northern Exposure (3 seasons), Arrested Development, Futurama, and Curb Your Enthusiasm. Update: I've add an old IDE/USB 200 GB but now all are full so I should buy another or rethink what I what to save or just see and delete some. The cutoffs are now mid-8.1, mid-7.7, and 7.6 with a few 7.6 and lower on the main drive.
My current desire: "library sort" so that a/an/the are ignored or placed after a comma, guess der/die/das and le ... would also help in comparing the Dish name sort with the IMDb sort except for foreign titles. You can edit the main drive names but the 14-character limit and only initial upper case preempts that. I did this for my Excel sheet so I could compare the top 250 on IMDB with my 1100 or so DVD listings. You really do not want ~20% of them starting with A/An/The. My entries to IMDB are currently only for those on the hard drives--630+ not counting all the series entries.
I also wish they handled a near full disk better. Sometimes I have to unload a bunch and reload them to add a big file.
-Ken