I've received mine now as well.
The build quality of the receiver and remote both seem excellent. Set up is straightforward, and to ensure the best mbs speed I can get I used ethernet extension plugs to allow a wired ethernet connection to the box under my Sony TV. My tv can only receive 720p, but it's good to know that this box is capable of 1080p when I upgrade the tv. Picture quality is very good on Netflix, and is an improvement over the netflix picture I previously got using my Wii wirelessly (Wired is not an easy option on the Wii).
However then we come to the Elephant in the room, which is Netflix is really the only Channel available now that I can see being used for extensive viewing. This product will live or die on the channels it can offer in future. I purchased it knowing that Netflix was really the only popular channel on there, taking into account I can always use it in future to upgrade a bedroom tv, but if it wants to be the preferred receiver in the living room, far more channels are needed.
I have taken a look at the Private Channels, but the ones that do look worth downloading just produce a "not available in your area" error message when I attempt to add them. For some this is obviously due to content rights restrictions, but for otheres it seems a strange decision. Both Justintv, and Filmon are freely available as apps on UK Itunes to use here in the uk, but these channels both produce the error message above when I attempt to add them to the Roku. Surely if Apple allows them to be used in the UK, Roku could?