Fiber is the dedicated connection between your home and the central office -- which also carries your phone and TV. In this respect, fiber is great for reliability and bandwidth possibilities (and differs from cable in that your internet connection isn't shared within the neighborhood, but instead isn't shared until you reach the central office just like DSL). However, once your traffic arrives at the central office, it's no different than any other ISP who manages large networks and connections to the Internet.
Once you get to the central office, you're part of the same cloud as everyone else and local conditions, neighbors in the same town, and traffic demands in other parts of the country can all impact your overall experience. Some of these are within Verizon's control, but many are not -- and the same applies really to any carrier.
Doesn't matter how fast you can drink, or how big a pipe you buy (say one capable of supply 25 gallons a minute) ... if the other end can only supply water at a gallon a minute, that's all you're going to get (and if there are several people who turn on the tap around the country at the same time from the same source -- you're going to get even less.
In short, faster is not always better on the internet. Depends on what and where you're going. YMMV.
