Just an observation on the hardware Zener compressor. Yesterday I had it on the 2 bus and the setting where it sounded the best, revealed zero compression on the meters. I'm sure there was some going on because those meters are pretty slow and useless, but having said that, the program sounded so much richer just going through the electronics.
So when evaluating the plugs, I'd be curious to know how they sound or change the program material with little to no compression - and if they in fact emulate the way the electronics of the box affect the sound.