Re: Old vs New
Same thing IMO, if it works then old vs new shouldn't really make a difference. After all a pickup doesn't have any moving parts and the custom has a ceramic magnet, these don't degauss under any kind of normal use/abuse.
That said many will say (and having one, I agree) that MJs pickups have something very special to them. It's like when the woman winds she adds a dash of magic in them.
Others though probably won't be able to tell the difference...
What DOES make a difference if you're in the US is the 21-days exchange policy.
If you buy a new pickup and for whatever reason isn't what you wanted you can return it in exchange of another similarly priced pickup.
If you're unsure of what you want AND live in the US then that'd probably be a good idea.
If not, like I said, same thing...