Not necessary, but fun. I have a pretty deep catalog of stuff now. The issue was consoldating to a new 2T drive that I picked up and going from 4 drives to 4 total. It was a big pain.
Its not all available, at leadt for free. Seinfeld isn't free and the TBS version is a nice transfer that isn't on Netflix yet. I have them all.
I like music, So if I band I like it on Letternan or SNL somewhere else, I save it. Yea its on youtube, but stuff like Neil Peart on Letterman is sweet to have is real HD.
Then tehre is some picture quality stuff worth saving - like the praying mantis from PBS (probably the best PQ).
Netflix is decent quality for a basic show, but the sound is still not as good as a HD recording from Dish. For the real action stuff, I get the Blu Ray version for teh best sound and PQ.
Not necessary though.
With other ways to watch those shows online, is it really necessary to keep all those recordings?
Give your hopper or EHD some breathing room