Isn't it so that depending on their specs, MOV's can "clip" those occasional transient peaks of current to your amps so your speakers can not express those flash cymbal crashes for example.
That's the reason that I pulled my Richard Gray MOV power conditioner out from my system and placed a Seimens Pro 140 at the circuit breakers. I'm in S Florida so it's a risk but I don't want any MOV's by my equipment. I think the Shunyata designer feels the same.
I have a tricked out PI Audio UBER Buss power conditioner though.