Hi
Have just registered to add to this topic.
I purchased the 8 channel version and have got 2 cams running at 720 on it. I believe you have to set all cams to the same res for the unit to work. I have attached a 500gb usb 3 drive and this is working fine - needs formatting from the machine as mentioned above. The manual states it uses a save method that records data in one constant stream from the inner to outer track and then overwrites, this is presumably to ease the life of the hard drive.
After setting my cams to 720 - the nvr found them and populated the basic details with no hassle.
I have tried to set the motion detection but I cant get it to work. I think it is more of an interface to the cams onboard detection rather than the nvr and as such would be very hit and miss for non matched hardware, though hopefully ONVIF may help with this eventually.
As i am running low res, on playback, both cams are shown.
I am currently exploring the remote access side of it as I intend for it to run in my attic. the software is very touchy about IE, my main pc shows the login screen but my laptop shows a chinese page. I have set the active x settings like for like and have downgraded to IE9.
An annoying aspect is that when remote accessing when you log off all the setup is lost, not the cams but the screen setup - i.e a 4 grid view.