I figure I might as well add my 2 cents to the Mo ' Joe.
In my experience, it's definitely more of a pickup for heavier rock and heavy blues tones. While you can use it for metal there are better voiced pickups for that from DiMarzio. If you're looking for a pickup that'll do instrumental shred stuff like the Joe Satriani stuff, it's great, but if you're looking to do more of the metal shred stuff, you will very likely want a bridge pickup that's heavier sounding.
For all you pedal and effects guys, the Mo Joe does handle processing quite well and also cleans up pretty good.
Overall, I'd say that this is definitely a very versatile pickup that would handle a vast majority of styles. Great 'rock' tone with harmonics galore. If you liked the Fred, you will love this. I haven't tried it in the neck position, but I'm pretty sure it would work in the neck if paired up with a higher output pickup in the bridge like a Breed or something.
As for pairing it up with a neck pickup, any of the neck pickups from the PAF family would work well like the Paf Joe, Paf pro, air classic, paf 36th, virtual PAF as well as the bluesbucker and the humbucker from hell. Basically, any of the pickups with more of a vintage vibe would work well. It also works well with the majority of dimarzio strat pickups.