For the last couple years our Time Warner Cable service has provided DVR service from Scientific Atlanta Passport which is intuitive and easy to use. I absolutely loved it.
Overnight Time Warner "upgraded" us to their new Navigator DVR system.
Without entirely recapitulating the two-page memo I wrote today listing the new service's deficiencies, I'll share I found that the Navigator is slower, more cumbersome, requires more clicks for many functions, has less information, is glitchy, and does not have "memory" of the last function you were working on which results in many extra clicks. The DVR menu also has the annoying habit of vanishing from the TV screen after only 15 seconds; per my previous comment about the DVR not remembering the last thing you were doing, if you were in the scheduling part of the menu, when you get the DVR menu back up you end up back on the list of saved shows.
I highly suspect the Navigator was a cost-cutting measure on the part of Time Warner, because it's certainly not providing better service.
In short, in my humble opinion the Navigator DVR is a piece of junk.
At least I found the four Stewart Granger movies I recorded from TCM last night, which overnight turned into pumpkins with "Unknown" titles which were labeled as "Adult" programming!
That is all.
September 2009 Update: After sticking out the Navigator for two months, we're switching to Verizon FiOS.