had two, both incredible. yesterday i ran a big muff w/ volume + sustain cranked into a seymour duncan twin tube blue with volume + gain cranked into a strapped bassman 10, with both volumes on ten, but the master at 3. no squealing until i was right up against the amp. (i was trying to pull of citizen erased by the way, not as easy as it sounds... the timing trips you up a bit).
by the way, that was with the power rails neck PU in the bridge for harmonics win. painfully bright clean, but wonderful crying sound distorted. not the pu for a one-pu guitar, it's a one trick pony but it does that trick veeery well.