Gbit fios here and been on fios for a long time, currently a sweet deal at $70 no fees no contract price until 2020.
There is no support for it, but you can have them light up the RJ45 on your ONT and use whatever router you want. You might run into some ordering issues, worst case rent their router for a month or buy one and resell at a small loss on craigslist etc.
TV complicates this, but you can go cablecard and use none of their other ripoff rental gear. YOU DO NOT NEED THEIR ROUTER FOR TV PERIOD - lots of misinformation online about this, stick to dslreports guides. Personally I ditched TV for nothing but 'net, unless you are a total sports junkie you can get pretty much anything worth watching.
I shouldn't have to explain this in 2017 but paying for local phone is for suckers only.
PS don't waste your time with their battery etc, the ONTs still cut off all but phone after 5 mins on battery, even if you don't have that service! Go out and get your own ups for ~$100ish and it will run the ONT and a typical router for a long time. (cyberpower PR1500 on sale is best bang/$ if your power is out often)
If you really use your connection a lot, look into rolling your own router. I run a nice fast pfsense box with lots of options turned on and a big fat VPN.
2018: at 120 Zen cores and counting, so pretty much done with intel on the desktop.
E5 2696v4 22c44t 2.2~3.7Ghz - The last great gleam of the pre-nerf HEDT era.
E5 1680v2 8c16t 4.5Ghz - "Yes Virginia, there were unlocked xeons" /weep for them.