So that is basically a humbucker-sized Pig '90 in the neck? I have been thinking that might be better than the Warpig neck humbucker for cleans. How does it fare in that respect? I find P-90s have more of everything across the spectrum (including more hum, of course!). My Stockholm-wound Nantucket (that was how it was ordered!) has made me a P-90 convert!
From what I hear the WP neck is somewhat good on cleans in its own way. It certainly does Jazz cleans. There is a clip somewhere of FourthFeline playing it and it sound great even though it was just played through an IRig.
The MQ neck is, yes a HB sized P90, the equivalent of the Nantucket. Suprising amount of power and yet so clear. Probably a bit of the goldstandard p90 just as the Mule is for the HBs. It was the PU that sparked my P90 love.
I must add that mine is currently guitar less as I have not found the fitting guitar or propper bridge PU for it (only tried RY and Aftermath to be fair as I originally wanted it for a single neck PU guitar which now has a manhattan). What I have found though is that I am 100% that it belongs into thicker guitars, like LPs and Explorers or SGs, for my taste. It certainly will cut through wood and breathe life into instruments. You get all the P90 goodness, that roar, the power, the attack, incredible clarity and such. Also the nicest bottom string definition I have heard on any PU. Really got that feel that it is just amplifying the strings, which was amazing. Neck P90s are so clear I feel comfortable doing (non overly palm muty) riffing with a good chunk of gain (Orange TT gain on 3 + OD) on my Manhattan neck in a semihollow. In fact I love the sound and that is a jazz PU.
Compared to the Supermassive neck I have it is much more classic in sound, less bass, less hot and compressed. The agression is more open. Clarity and definition are big on this one. Would actually love to get them side by side some time. Cleans are amazing on the MQ but only good on the SM for those reasons. While having that P90 character in the midrange very strongly still compared to the SM it does less roar more scream. Heck this is the neck PU that can do the best screaming sound I have ever heard out of one. Roll back tone and volume though and it can sing like wow.
The MQ gives you the ability to relive classic sounds and push boundaries. It can scream or sing at your command.
I cannot claim to know too much about your style of music, but from what I gather about your preferences in PUs I am very confident you would love a MQ neck. Definition, clarity, dirt,...it is all there.