Thanks this is helpful. I am in the market for a PC as well especially since I want to integrate a USB dmx interface. Doesn't have to be a laptop.  open to any suggestions.  

Yes, you should look into the camera Specs, since some have shorter ranges than others. So the height of your ceiling may play an important role in your camera choice.
I think the Intel RealSense may not offer a deep enough range for your needs. The Kinect V1 and the Orrbec Astra offer fairly similar ranges, while the Kinect V2 offers a longer range.
You should also consider the lens  used in each camera, since a wider angle lens will provide a larger 'active' area for tracking.

Since you won't need skeleton tracking, the cpu usage of the OpenNi actor will be much less (compared to Skeleton tracking) and will initialize more quickly (Skeleton tracking can take some time to activate).

Do you work on Mac or PC? Do you have specifications for the delivery computer system?

ay that all supported cameras are solid working on Windows, while some users have had trouble with Kinect V2 on Mac.

 An installation where the camera will be suspended from the ceiling looking down on the ground.  As people enter the field of view I want to trigger LED lights, sound, video.  Since its an installation with people who are not performers - what happens in the space will be unpredictable.  The installation will be placed in a room and left to run w/o operator input for 4-6 hours at a time. 

Doe that help? 

Please tell us a little about what you need to accomplish? Each camera has specific strengths. 
In general I would say that all supported cameras are solid working on Windows, while some users have had trouble with Kinect V2 on Mac.