| There have been a few threads about this recently.
I replaced the neck on my EB Stingray with a Moses graphite replacement neck some years ago. I sold that bass a couple years ago along with the original neck. I never could get to like the post Leo Fender Stingray sound much.
The Moses neck was well made, easy enough to install if you're handy with tools. You must install the neck with threaded inserts, not typical woodscrews. Moses supplies the inserts and bolts along with a jig and instructions to install them, but ask for them when you order.
You should have a drill press to drill the holes in the neck for the inserts. If you can't do this yourself, it would probably cost about $75-$100 for a tech to do it.
The neck fits the body nicely. Frets will almost certainly need levelling if you want low action. Fret ends are well rounded.
As far as a change in sound-I wouldn't consider it much of an improvement. Slightly more sustain which I didn't need anyhow. Slightly more even response. Slightly brighter sounding. None of this was noticeable when playing with a band live or when mixed in a recording studio.
One advantage-the neck doesn't change with differences in humidity and only slightly with a drastic change in temperature. So once you adjust the truss rod that's it unless you change to different tension strings. Tuning is very stable-unless you hit a tuning key it'll stay in tune for weeks.
I wouldn't do it again. I don't particularly care for the feel of graphite and prefer the Stingray's wooden neck and fingerboard. Then there's the extra cost.
Moses customer service was good. I can't fault the quality of the neck or Moses service. It just didn't do much for me and wasn't a worthwhile improvement. For a while when graphite necks first came out there was a lot of hype about how they were the future of bass necks. In my opinion that's all it was-just advertising hype aided by the writers at music gear magazines. | 
