Thursday morning about 01:00 EST the operating system of my FIOS DVR was replaced. The menu operation is now far slower than it was - that is, getting a program to play or stop or delete.
You can tell the new OS from the background color - now black. I suspect the slowdown is the addition of advertising to most every screen. Like "if you enjoyed this program, try the following from video on demand" with photos of posters for various programs and movies.
It is ridiculous for Verizon to downgrade service like this. FIX IT!