OK, according to the warranty cards, my MM neck is 17.5k :!: :o & my CS neck 8.2k.
The baby had an early night & I got stuck in the office late, so haven't had a chance to A/B the two through my Mesa at proper volumes, but here are a few comments from playing through my VooduValve on headphones:
The MM has a LOT more output. It also seems to have more bass & sound more "compressed" than the CS.
The CS seems brighter & more "open".
Both are good at neck leads, but you hardly even need to use a pick with the MM :) - it does that thick fluid legato neck lead noodling so well :D
But IMO the CS has a far superior clean sound - if neck cleans are important, then it's no contest - CS every time.
Hope this helps...