I recently bundled all of my service with Verizon FiOS. I'm probably saving about $20 a month now with their new 4-pack bundle (TV,Phone,Internet,Wireless). It's really more of a simplicity thing for them, to put everything on one bill. No complaints here though.
The install took quite a while, about 5 to 6 hours. Not having had High-Def before, the upgrade was well worth it. The only thing I do not like so far is the router. All of the devices installed (router, set top, DVR, ONI) are monitored by Verizon, which made me a little uneasy about leaving my computers out there unprotected. I fiddled with the router configuration for about an hour, but ended up choosing to disable the wireless on the Verizon router and connect my old Linksys Router to the new router, leaving the new Verizon network as a DMZ.