I'm a recent FIOS TV Sub
First let me say, I was quite glad to ditch my Comcast, then recently Time Warner cable modem service for FIOS internet. That 2MB upload is nice for working from home & uploading photos. On to the TV service...
I've had it a week. HD picture is great, SD's seem slightly better than Dish - not great, but certainly no worse, at least on the channels I watch. I have 1 SD STB and 1 HD STB, with FIOS Premium and HD for $50/mth plus tax. It is most equivalent I think to Dish HD Silver + Locals as far as channel lineup, which is more expensive per month. The interface isn't as good, yet is being worked on as others note. I do like the weather & traffic widgets.
As far as hookups, I will explain. The fiber cable comes to a box on the side of your house. From there the fiber is converted to Ethernet for internet (and goes to a router in my office) and Coax for TV. So, as long as your cables are good, they can use existing wiring for TV, as they did in my house. One thing to keep in mind, the internet router has a Coax connection. It just needs to be connected to a Coax splitter. The STB's get IP addresses, and get the guide data and do VOD via IP. For whoever aksed, if you don't use an STB you can get locals and public access channels 2-49 just by hooking directly to a TV. Also, on the HD box, both HD and SD outputs are active. I have the SD output feeding a 15" TV through the wall in my workout room. So far I am happy and plan to cancel Dish this week. I have really no complaints with Dish, but a comparable package will cost more $$$ and I'd need a new Dish on my roof to get all of the Dish HD channels, many of which I don't care about (Voom). I do miss the RF remote, but I recently got a Logitech Harmony anyway. Oh, and I do miss the on-screen Caller ID. My advice to Dish - if you wish to stay competitive, lose the upgrade fees on leasing new equipment and stop the nickle & diming, OTA guide data was free on my 811 without locals, but not on the 211 or 622 from what I've hear. Oh, and quit releasing buggy firmware!