I just A B'd the two models with the same SMF.....There is a big difference, the MZ sounds better..I figured it was the speakers, so I routed the WK into the stereo in of the MZ..The WK sounded better, but the quality sound from the MZ GM tones were still better...They seem punchier..I don't see any different changes in EQ between the two, so my guess is the MZ just has a better set of GM tones, or maybe a better output conversion..