I have no complaints about mine, but I've never owned a higher end bass. To my ears it sounds pretty transparent. And I like that it's simple, without active tone controlls. But I've heard some criticisms of it. Has anyone upbraded the preamp (but left the pickups, tone controls etc. the same)? Or tried with an outoard preamp like the Sadowsky? Maybe tried something with 18 volts? I'm curious to know what people's impressions are.