Im not sure you will get a real earth-shattering difference if you change pick-ups and electronics. Strings, yes. But why spend money for a different headstock? Squiers are great basses
my experience exactly. My 5er jazz are similar in fretwork to the Fenders, but the 4-string jazz is a better bass than every Fender I have compared it to so far. An excellent bass. Indonesian built. I don't play 4s any longer, but i can't bring myself to part with it. I need therapy.I have tried many Affinity basses that I was expecting to be only okay-at-best. To my surprise, I found many of them very lightweight, playable, and good-sounding. The fretwork was iffy in some cases, but that's often true of USA Fenders costing many hundreds of dollars more.