Hey.
I looked into this from liverpool exhaust fully installed. Didint go as far as price as i ha an awesome greddy on the car but if cash allows in the future i would seriously consider it.
But note. Its hard for the authorities to tell but if they do pick it its a defect. Nsw ( at least ) does not allow any moving parts in the exhaust system.
If you go ahead with it i would be very interested in meeting up with you to check it out.
The guys at liverpool exhaust are very helpfull and will tell you the truth about anything you want to know. Probably becuase an exhaust note doesnt lie so they are strait up and are very helpfull.
From memmory the varex is pretty good cost wise as well. But i dont know what sort of tone you will get. Give them a call.