I switched from Comcast Triple Play to Verizon Triple Play a month ago. My Internet download speeds at both vendors was/is comparable: 100 MBps. I have FIOS fiber optic to the box on the side of the house; from there, it travels via my installled copper wire cable. PC is connected to modem via Ethernet cable. This observation is purely about the ability to access the Internet on my PC. My basis for comparison is my previous service with Comcast.
As the day goes on, accessing web pages becomes increasingly difficult, no doubt due to that blame-for-everything-the-vendor-can't-fix thing: "CONGESTION." Around dark, it becomes virtually impossible to even access Speedtest.org; if you are lucky enough to get a connection, the download speed is always what Verizon promises.
I NEVER had this problem with Comcast, so there is something about "CONGESTION" Comcast has figured out, but Verizon hasn't.
In my house, at this point, the Internet WWW is functionally inoperative after 5 PM. If the situation cannot be improved, then I will be returning to Comcast. There is plenty I don't like about their operation, but at least they provided the Internet access they promised.