We have an 8 camera system with an 8 channel DVR at our theatre, and I absolutely love it. We have cameras 1 & 2 over each register on the concessions line, camera 3 pointed at our Screen 1 parking field, camera 4 pointed at the boxoffice and Screen 2 parking field, cameras 5 & 6 "were" mounted in the projection booths on a sliding rail to monitor the platter feeds, camera 7 covers the stock room, and camera 8 covers the lobby.
With digital projection being installed within the next week or so, I'll move the cameras that were dedicated to the platters to other areas of the building.
Best thing I like about our DVR is that it's internet accessible. I can sit at home, the office, or even while I'm on vacation and check out what's going on at my theatre.
Got mine off of Ebay (Zmodo brand) about 3-4 years ago, and have never had a problem with it yet. Ours are all hardwired, which is what I preferred. I keep the DVR locked up in the mechanical closet with all of the other network stuff, and have a 17" flat screen monitor hanging on the wall - visible to the kitchen.
One thing I have noticed, and would do different next time is NOT to display the register cameras on the screen. The crew now knows the "field of view" for the cameras and purposely stand in the blind spot to hide and text. They could use the blind spot for other purposes too, but so far I've only caught them texting or just plain goofing off.
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