Hmmm.....i wonder is there any similarities between the Riff Raff neck and MQ?
Think more in opposite directions, to a certain degree. Bear in mind, I have heard the Riff Raff only once - and have used the M.Qs only with moderate gain, or clean. The Riff Raff is clear, bright , edgy - the M.Q is fluid, glassy and much more rounded. The M.Q can also give differing degrees of bright and defined, through to 'chewy' and thick, with tweaks in pickup height, whilst still remaining articulate. The M.Q delivering that type of cut and clarity associated with single coil pickups, but with the push and 'fatness' of the windings. they are Alnico V bridge, Alnico IV neck.
You could say that the R.R are very bright , open - and cutting for a
vintage humbucker - and the M.Q very fat, warm and assertive for a single coil.
I hope the others can chip in with more detailed information / perspective. :)