Depending on the size of your screen and the length of the run, you probably won't notice much loss in quality.
The boxes Verizon uses are the same hardware as Time Warner/Comcast were using when I had FIOS, and BOTH companies were having assloads of trouble with HDMI, so I suspect they probably aren't just pulling your leg. I've since given up on TV and instead have taken to watching grass grow as it's generally more intellectually stimulating.![]()