I have had a new system installed including a EZH4 Lite DVR. Not seen them get a mention yet, so my observations so far:
You can only have one connection at a time (the directly-connected monitor aside). In my case, if my Kindle is connected I can't view on another onsite PC.
If trying to view offsite, the same applies - an onsite PC will prevent access, as will another offsite.
One query from me: twice the DVR has gone offline. It beeps for a while, then re-boots and back to normal. I'm guessing that it shouldn't do that?