Do you have the remote code for this device?

I dont know if there is one, sorry

can i use this to get netfix?

Nope. But it is one of the best media player if you download to your portable HD and then connect it to this player.

Can this play MP4's with 6 channel audio? and does it upscale?

Does not work with all MP4. It uses the same MP4 format that is used with apple products. I am not sure about 6 channel and to me it does show upscale quality but it also depends on source. Heads up too is that I notice sometimes there is a buffing on the hard drive so try to get one that has higher RPMs,so it will not pause movie when you are watching it.

Does the Nbox play true 1080p or just upscale 720p to 1080p output? I've noticed the same movie files are much more detailed when played on my computer.

I played this unit on both of my 1080P TVs. One is way more detailed than the other. There is about 5 year difference between the two. So I think it matters on your TV. Also this unit does not play all files as stated.