3 years ago, I had 15/5 FIOS and had trouble with slow load times for streaming services including Netflix (we now all know about those problems) and MLB.TV (heavy user). I switched to Comcast (to try and fix the issues as well as lower price) and had a very good experience. Very fast load times, no stuttering, good up times.
As Comcast prices have risen in my area, I decided to try both side-by-side to compare. I had 50/25 FIOS installed but kept by 25/5 Comcast Xfinity running as well. Other than the modem, I'm using the same 1 Gbps Ethernet switch all over my house and ALL of my devices (Roku, streaming DVD, etc) are directly connected via Ethernet. No wireless connections and all of my devices have been power cycled for a clean boot with the new system. The only difference is the modem and the source of the broadband pipe.
The good news is that I'm getting 60/30 service with good ping based on several download sites including the FIOS test site. The bad news is that the MLB.TV and other streaming services on FIOS are all stuttering like crazy ... sometimes the stream pauses all together. Obviously this is unacceptable for watching sports or movies.
The FIOS stream takes a relatively long time to load (5-10 seconds) compared with Comcast "instant" start and will often stop, buffer for a few seconds, jump back, and then go forward for 30 seconds ... running out of buffer and starting again. Other times it will play but at a reduced bitrate (pixelated resolution). None of these problems exist when I use the (still active) Comcast connection and modem. I had these problems with FIOS 3 years ago, and now they have immediately remanifest when switching back. I'm frustrated.
If this continues, I'll need to cancel Verizon FIOS and continue with Comcast ... the price difference isn't worth it.
Any thoughts from support? thanks.