Re: tonal differences betweeen wax potted and tape?
There's a tiny bit more 'clang' and ring when the covers aren't potted.
If you tap on the pickup or the body, the potted one will sound blunt and dead.
If you tap on the unpotted pickup, it'll have a metallic ring. When actually listening to the tone, it's hard to tell, but the potted one is usually the drier sounding of the two.