I fitted the P pup and a jazz one to my Squier P/J bass.
I mostly use the P pup though, and it is a massive improvement over the stock pup. Hotter output and makes the bass punchier sounding than before.
+ they seem well made too.
I got one when they first came out and they were really cheap, I think I paid £30 for the P pup.
If they are still that price then I would recomend it.