Can I hear some differences? Sure. My Stingray and my Precision don't sound all that much alike, which is why I like having them both. But I'd bet that if you secretly made some changes to one or the other, recorded before and after samples, and asked me to identify which is which (before or after) and tell you what the change was, in many cases I wouldn't do much better than a random person would do by simply guessing.
Having seen the occasional A/B test here and also on some recording forums, I've concluded what I suspected all along is true. The vast majority of people who claim they can hear those subtle differences and consistently identify them time after time *SERIOUSLY* overestimate their abilities. That's not my opinion, that's a fact that the tests demonstrate over and over again. Are there some people who picked out the differences in every one of those tests? Sure. But then again, there's always some sports averse wife who makes her NCAA tournament picks based on the cuteness of the schools' mascots and ends up getting EVERY game right, much to her macho sports junkie husband's embarrassment. So it's certainly reasonable to assume that at least some of those who say "See, I TOLD you I could do it!" have simply guessed right.
The other fact that comes out of these tests is that the stronger a person's guarantee that he can do it before hand, the more and varied the excuses are as to why they couldn't do it in THAT PARTICULAR test. The funny thing is that when they try to assert that they really can do it, just not under that particular set of circumstances, their excuses are EXACTLY the reasons why so many changes are simply too subtle to hear in a recorded mix or in a live setting, especially factored into all the other differences between two basses.
Now, having said that, I certainly agree that it's a lot of fun to tweak, to buy/sell/trade, and simply to try other basses. If you keep things in perspective (for example, accept that only 1 in 1,000,000 people in your audiences will ever notice, let alone CARE) and don't let it turn into an "addiction", then have fun trying things and you'll certainly come across occasional changes that make a noticeable and/or meaningful difference to you. And THAT'S what makes it all so much fun. But if you try claiming to me that you can CLEARLY hear the tonal differences between 1963 Fender Jazz that has been stored in a tweed case versus an identical 1963 Jazz that's been stored in a black case, you're going have to get it right 100 consecutive times before I'll stop laughing derisively in your face.
Count me in among the Philistines!
