My preference would be to go with Tivo but not because of the service it provides. I hate the idea of having to pay $4.95 for "Tivo Service" and the fact that they are watching everything you watch to sell you stuff.

What I do like is that hackability of the units. One of my friends works for Tivo and sent me a bunch of links on how to open up and hack the crap out of it.
10 Hours of record time not enough? Open it up and add a 60 Gig drive so you now have 240 Hours. Don't like them snooping you? Write a small ksh script to stop sending extra info. They basically are just Lynux boxes with MP2 decoders on them. When I get back to work on Monday, I will forward the links to you.

Also, I try to be an anti-Microsoft kinda guy so buying UltimateTV just wouldn't apeal to me. I also don't like Msoft knowing what I watch.

Greg