Yes, sili NPN's are pretty hard to differentiate soundwise, hence my question.
I've built tons of mosfet projects and so far I've been able to single out the type of mosfet trans I really like to work with, as those have very different character and behave differently in a gain stage(s) configuration (ex: J201 are very meaty, 2N7000 are much tighter etc...)
J201 isn't even a mosfet, it's a Jfet. J201 and 2N7000 won't normally even operate in the same circuit (DC source follower being an exception), J201 is depletion mode (normally on), 2N7000 is enhancement mode (normally off), so they have entirely different biasing requirements.
Similarly, when you reference "JRC" and "TL" op amps, I assume you mean the common RC4558 and TL072? JRC is a brand, they make hundreds of different op amps, and Texas Instruments make thousands. You could mean JRC1458 and TLE2074 for all we know.
Anyway, they're both quite different op amps. The 4558 is a general purpose bipolar op amp, most at home dealing with medium to low impedances, and has relatively poor noise performance if used as a front end input for a guitar effect due to this. Quite at home after the guitar has been buffered though. The TL07x series is BiFet, with fet inputs and bipolar output, it is designed for high impedances, and has much better noise performance than the 4558 when dealing with guitar impedances.
So one does not sound "better" than another, at least not universally. It's entirely dependent on the circuit it resides in whether one will have better performance or "sound" better than the other.