In the spirit of the OP, I obviously agree that a good player is going to sound good, period. HOWEVER, I had a similar experience as you somewhat recently. Saw a band in Detroit (blues oriented 5 piece) and the bassist sounded great.... clean, great time, great groove, nice fat tone.
He was using a Fender Marcus Miller 4 string with roundwound stainless steel strings and had an old SS Ampeg head and a 'no name' 115 cab. It was full, fat and warm... and... it made his bass sound like a PBass with flats on it. I actually asked him if he was using flats and he kind of bummed out, since the 'sound in his head' was a more bright, J bass tone. My guess is, it sounded a little more growly and bright up on stage, but without a more articulate rig with more power, etc., that tone just never made it past the edge of the stage (there was no front of house support on this gig).
Good playing AND a rig that is voiced and has the power to deliver 'the tone in your head' to the audience is the best combination IMO and IME