(Serious) problems with the stock bridge: Too heavy Forced me to shim for a decent action Hard to fit strings through (especially B) Strings don't align over pickups G string falls off the neck It felt like the stock bridge was made for another bass, but found its way to the Ultra Jazz by mistake. It was an unfitting component of an otherwise great bass. The Hipshot bridge made the bass feel & play corresponding to its price segment. (Trivial) problems with stock knobs: Too many similar knobs Risk of turning the wrong knob on stage Following the tradition of Marcus Miller, I simply replaced the first two plastic knobs with P bass knobs. Now I see exactly where the basic controls end and EQ controls start. Much less room for mistakes. I recommend those mods (especially the bridge) to all Ultra Jazz owners. They really made a difference for me. Now I enjoy the bass much more.
I got chicken head knobs, put them on everything, all basses and both heads. Color coded on the head so at a glance I can see where everything is.