re: P bass vs jazz bass

I've always preferred the Jazz Bass on tradition. I think it is the gold standard, sort of the "reference" bass sound for all of rock history.

Not to discount the J, I love them, but you have the benchmarks mixed up. It was the Precision that was the specific instrument used by all the prolific first-call session bassists in the major studios, from Carol Kaye on the West Coast to James Jamerson at Motown. Even into the 60s, when the J was the new and improved and the P was the older and more primitive predecessor, Kaye has said in many interviews the top producers would specifically request her and fellow rats bring their Ps. They simply work perfectly in every musical context in which they are placed.