I got rid of all my Panamax gear, after reading how MOV's are not dependable at all. And they restricted the current as well.
I am now using Brickwall units, high current models that don't restrict the current, and are made just for power amps. And by design, they do some nice conditioning.
I recommend Brickwalls, as they will never fail, under any condition..and they dont restrict the current whatsoever. Probably the best decision I have made in the past 14 years being in this hobby. Total peace of Mind..no feeling is better