With FiOS - the ONT has an extremely strong signal.
Verizon has cable boxes that have no guide info, no video on demand, and they are strictly cable boxes that give you only the channels. These are model DCT 700.
You could without upgrading anything (routers) get 15.
The problem comes in when you want the standard Verizon Cable boxes, that do the on demand, the multi room, the Info Guide, the widgets.
Those boxes require an IP Address from the router, and they travel from the router, across Coax Cable to the cable boxes.
That is done by a technology called MOCA.
With the older Verizon Routers (Moca 1.0) you had the 7 IP enabled set top box limit (on top of that 7, you could have still got the extra DCT700 tv converter boxes to make a total of 14 or 15 without any headache or hassle)
This could have been overcome by verizon without changing the router, by adding additional hardware at your house. The Verizon Tech has a Tier II line and Network tech's to call on when he doesn't know something.
With the Newer Verizon routers, (Moca 1.1) you can get past that 7 limit, as it increases to 14 or 15. The caveat is that all the devices (as noted above) have to be moca 1.1 compliant. That means you would need to double check your cable box model numbers. If they are all 7xxx series Set top boxes, then you would be fine. If you had any 2500's or 6xxx series set top boxes, those would have to be upgraded along with the router, or they would have to go back to the old way.
Either way it could have been done, the newer router, would have made it easier for everyone involved, especially if you had all 7xxx series set top boxes.
If you are getting poor pixelization and poor signal with the more set top boxes you are putting on, then that is not a by product of the Verizon FiOS terminal, that's a by product of Wiring. So you, or someone you bring in, or Verizon would need to find where that problem is and fix it for you.
