I can relate to this - although in a non-conclusive way i guess
I bought my USA 2009 P Std from a chain shop in my town. It was excellent - setup was fine, sound was spot on, everything I expected and wanted from a USA P at that price. I bought my Geddy from the lovely chaps at Wunjo in London and that was probably the best setup "out of the case" bass ive ever played, with the exception of my 2011 Rick (sadly now back at the factory after the paint fell off it, different story).
On the other hand, i went to the same chain shop I bought the P from to try out some jazzes and other USA P's before I took the plunge on the Geddy - all from 2011/12 - and all of them were shocking. Badly set up, rattling in the neck - and worst of all, two of them had significant nut problems on the A string resulting in dull "clacking" string sound. Wouldnt have spent a grand on any of the four I tried! I do also twang a little bit of guitar on the side so tried a few SG's out and they were out of tune, all over the place. Whether or not that is indicative of anything I dont know.
So I think the old adage applies - you gotta play a few before you find the right one...