I further note that my gut feeling is biased by the fact that there are far more set-screw connections around where I've been than compression connections. Therefore, I'm a lot more likely to see set-screw fittings that have come loose, just because of the numbers. So, if there were a lot of compression fittings around, perhaps I would be seeing those conduits hanging by the wires, too.
I think that assumption is right on the head... When it comes to conduit coming apart, ground path and survivablity, there is only one that does better than set screw, and compression, RMC threaded connection.
Spare going to RMC, survivablity with EMT is going to depend mostly on support, and the 1 hole strap is the culprit there. A mineralac, or 2 hole strap will help if not on strut. When it comes to ground path and survivability (set screw or compression) steel is better IMO. You can torque it much more than die cast, have a better connection, and be less prone to breakage down the line.
I would think any exposed conduit in a prison would need to be RMC just for security/safety reasons, if not vandal resistance.
