I may be incorrect on some of the details here, but I am sure about the feature that I (and I assume everyone else) has lost in the latest update to the DVR system
Firmware version KA15.09.16.10 is what I have listed in my Settings screen, and after talking to a 2nd level tech support rep, that is the latest.
Here is the feature:
Previous to this update, live TV recording made it possible to hold (in the DVR buffer) the portion of the channel you were watching before changing to a 2nd channel. If you were watching ABC for an hour, then switched to FOX, and then back to ABC you could still rewind ABC up to that full hour your box was on. Considering the new Quantum media server box (the main box) contains 6 tuners, this was the normal behavior when all DVR resources are available.
After the firmware update, this is no longer possible.
The DVR deletes the buffer from the previous channel immidiately and starts recording only the currently viewed channel. And this has been tested in a five TV household, with a media server main box and four client boxes (IFC?), with NO shows being recorded, and only one TV (and box) turned on.
If you were unaware of this change, test it for yourselves (and here, I may be unaware of additional circumstances - I do not know exactly who gets this particular firmware). But I can say without a doubt, as somebody who has been accustomed to this feature for the last 2 years (1 month+ with the new Quantum hardware), it is a considerable downgrade in both casual TV viewing, and the loss of an extremely useful feature.
If you agree this needs to be returned to the FIOS DVR service, let them know about it.