Seeing as how I've now got all three pups, I thought I'd do a review of how they compare. They're fitted in three different guitars made from similar woods, and here's how they sound:
Riff Raffs
I have a calibrated set of Riff Raffs in chrome with two conductor wiring in an all mahogany Epiphone SG.
The neck pickup is great for bluesy styles, with a nice bit of bite and no mushy tone whatsoever. I usually find neck pickups to be really woolly, but the Riff Raff is nice and full with plenty of clarity. A great all round blues tone, but with a slight edge.
In the mid position, you get a great "Red House" tone by rolling off the treble pickup volume a touch and rolling off a bit of tone from both pickups. A nice chunky tone with plenty of depth and character. It also does a great "Paperback Writer"...
The bridge pickup is what I bought the set for - with the right amp settings it's Angus. There's a great bite to the tone, although that is at the expense of some mids. Riff Raff is a great description of the sound, as it's that wiry, snarly tone Angus got for that track that really characterise this pickup.
Mule
I have an open coiled and tapped zebra Mule in the bridge of my cedar body/mahogany neck Gordon Smith GS-1.
Compared to the Riff Raff, there are more mids and a fuller tone. I can get a great "Jailbreak" (by Thin Lizzy, not 'DC) vibe and with a cranked valve amp you get a superb rock tone. Nice and full.
When tapped, you get a very useable single coil tone although it is a touch thinner than a true Strat sound. Very good for bright, clean parts of a song like the verse arpeggios of "Learn to Fly".
The Mule is billed as the all rounder, and that's exactly what it is!
Mississippi Queen
I have a tapped chrome Mississippi Queen in the bridge of my cedar body/mahogany neck Gordon Smith SG-1.
Compared to the Riff Raff and Mule, there's more bass and lower mids. There's loads of clarity, even though this is one thick sounding pickup with a nice biting treble. Classic P-90 tones. Again, the description of Mississippi Queen is perfect for this pickup as Leslie West's tone on that track is what you get - a beefy and meaty humbucker-beating growl.
When tapped the treble is still there, but it's more rounded. Whack on a nice chunk of gain and you've got "Paranoid" perfectly.
So there you go - I hope that's of use to some people!