Hello there. Although I do not live in Montgomery County (I'm in PG), I have both the Tivo box and the Comcast HDTV DVR, so I feel that I am somewhat qualified to give you an opinion. Hands down, the Tivo box simply blows away the Comcast DVR as far as features and ease of use go. The only reason I use the Comcast one is because of its ability to record HDTV and I have actually been thinking of getting rid of the Tivo simply because itâ€™s a bit of a hassle to use with the Comcast product. I have heard that Comcast has been working with Tivo to integrate the Tivo software into their boxes, but I have no idea how far into that future that will be.
To address some of your specific questions, I do not believe that it is possible to share media between machines. To my knowledge, there is no way to hook the Comcast box to a home network, although there is a USB and firewire port on the unit. I think this is more for Comcastâ€™s use than ours though.
Season Pass - The Comcast box will do a "Series recording", but it's not very smart when it comes to identifying conflicts.
Performance when switching channels and moving between menus is comparable to Tivo, in my opinion.
In Comcastâ€™s defense, the one thing I do like is the integrated dual tuner that will allow you to watch one thing while recording another. I find that handy.
Hope this helps. If I can offer any additional assistance, please let me know. I have actually been trying to convince the wife to let me switch us to DirecTV so that we can get the NFL Sunday Ticket and the Tivo but she is worried about the weather affecting the picture. I guess there is something to her concerns.......