Depends. If you're only getting internet, I would take Fios over cable any day. More reliable, consistent bandwidth, no throttling or traffic shaping, relatively cheaper. For TV, the Fios channel line-up isn't that good.
Only drawbacks to Fios..
- Gotta commit to annual contracts if you want the discounted price. Not a big deal, but if you end up moving and your new residence doesn't have Fios, then you gotta pay the early termination fee.
- Can take forever to install. I don't know what it's like now, but I've heard it take 2 - 3 weeks from the time you order to the time it's actually installed.
- Gotta set aside some space for them to install the ONT
(Optical Network Terminal) and the battery pack and some other networking gear. Usually wall mountable in your garage or basement.
If you sign up for their Fios internet/phone bundle, DO NOT allow them to pull your copper telephone lines. I've heard some cases where they do this without asking. If you ever decide to switch back to regular landline phone service or DSL internet service, it will cost a couple hundred dollars to re-install the copper lines.