For those that do this, how does it work? I have a POD HD500 and right now am running it though a cheap PA. It does not have the 'amp' feel. What confuses me about this setup is that you are putting a modeler into a modeler. On the Mustang is there a way to bypass the preamp and just run it into the power amp disabling all modeling? On the HD500 do you run the full sims and have the cabs\mics on or off? I was also thinking about getting a tech 21 power engine, but came across one or two reviews of people that use the HD500 in front of the Mustang and love it. If it is that great I would rather go this route. Any info on this setup would be greatly appreciated.