I've been using the Netflix on my 360, and so far I've been impressed with it. The only thing that I have a bit of a problem is that I do have to use a computer to add things into the Queue, but I normally have my laptop nearby so it's not that big of a deal.

Between that and my S2 Tivo, I'm pretty happy.
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--Ben
78GB MkIIa, Dead tuner.