[twindman]

One advantage to hard-wired is it will catch a problem in your cable and connections to the rig. I have seen on here about the junction on the back of a rig where a wire will come partially loose. This can cause one line to fail or even burn up the connection. If you have a portable, then it would not catch this early. I agree about if they go bad and for some reason the bypass in the Progressive doesn't work it will be a problem to get it working quickly.
I also worried about theft on the portable, but I haven't seen anything about people losing them. I am not sure if the portable has some sort of remote readout display. I use my hard wired display all the time to see if the power is ok before I start and monitor the voltage levels during a heat wave. I have seen several places where the power dropped and the unit shut down the rig for a couple of minutes. Then I would monitor the voltage on both lines to see if it was safe to start the A/C again. If not, I would shut everything down until I could safely start the A/C.