Well, my setup is like this. I have fios triple play.
Room with actiontec router (fios ran coax to the router) and desktop pc, and the desktop pc is connected directly to the router. There is also a tivo dvr in this room connected with ethernet to the router. The coax coming into the room is split before being connected to the router to provide a tv signal to the tivo.
I just purchased an actiontec moca adapter for the room in another part of the house that has another tivo dvr, as well as an htpc. Like the other room, there is fios coax coming through the wall to provide the tivo dvr with a tv signal. I am using a splitter that I purchased, and split the coax so one wire goes to the tivo and the other to the actiontec adapter. The actiontec adapter is then running an ethernet cable to a network switch to provide both the windows 7 htpc and tivo with internet.
The adapter is working great in this room, internet speeds are somewhat faster than my wireless N adapter I was using previously. But the main benefit I was looking for was to be able to transfer large files from the desktop in the first room to the htpc in the other room at faster speeds than wireless. However, I am only getting around 10 mb/sec, which is what I was getting using wireless n adapters. If I wire these two computers together with a patch cable I get around 70-100 mb/sec. Any idea why both computers which show up as connections in the routers control panel aren't able to transfer files back and forth and closer to wired speeds?