I have used three Canon VC-C4's for an annual religious conference (combination business meetings / worship ceremonies) for about 10 years. 2 are stacked one above the other on a metal bracket I made, the other sits on the opposite side of the stage. They live on top of metal poles with power and control routed down through them. The control lines are about 200 feet long and run to a Telemetrics controller in the control room. The Telemetrics controls up to 4 cameras, (one at a time) and has 4 "presets" for each camera. The presets save pan, tilt, and zoom information for quick recall.
What I've learned:
*) Have a tally system, or at least a Program monitor for the person controlling the cameras, so that they are less likely to move a camera that is "live"
*) Impress upon the camera operator the importance of double-checking which camera he thinks he is about to move....if you press a preset button, the camera moves at it's highest speed, so you don't want it to be "live"!
*)The quality of the VC-C4's is just barely acceptable...I would rent Sony BRC 300's (or, drool, 700's) if I could.
*) You can send 9600 baud control signals down 200' feet of wire, even though no one would recommend it.
*) You can pan a camera "live" if you have to, but the Telemetrics controller is a little "Jerky" at the slowest speed (Just barely moving the joystick)