I agree if you dont already have a P, then get one.
the JC is an awesome bass, but it isnt as... versatile? in the way the P bass is. The P is just a beast in the backline.
I buy MIM fenders quite often, and just drop in a new pickup. usually nordy's. the RW P bass has 1/4lb'ers i believe, which can be easily achieved by buying a MIM P and some SD's.
if youre looking in to saving money, go that way. but if youve got the cash, the RW bass is a purty axe.
Problem is, by the time you buy the quarter pounders, you have almost as much into it as you would by just getting the Waters bass, which also has a brass nut, and those looks you mention. Could put in a brass nut too for a little more $$$ but again by then you almost bought the Waters, the savings isn't that much.
I considered buying this bass and was going to get it until I found an equivalent that I really like. It seems like it would be a great bass.