The quality of Comcast's service depends on location. If the wiring in the area is good and the headend is not over-subscribed, latency will be good and bandwidth will be acceptable. However, Fios uses fiber, which means that the connection quality to the headend will either be perfect or not working at all, unlike coax which is susceptible to electronic interference and degradation due to aging of copper infrastructure.

In my region near the airport, Verizon seems to be over-subscribing the headends. As a result, my download bandwidth has decreased over the years. Despite being on the one gig plan, I usually only get 300-500 megs down, but I get 1 gig up.

On the other hand, my neighbor has a business plan from Verizon and pays a bit more than I do on the residential package. However, they get a solid 1G.