@challengeofthegobots
I have been recording for 12 years now, 8 years of which professionally. It is my job and chosen career and I can tell you with a straight face that RECORDING, no matter how high end the equipment and topnotch the acoustics of the venue is, will always have a less-than-perfect representation of the source. Yes, even with your $2,000 Neumann mics and $3,000 mic preamps. Because in itself, digital media (even at 96KHz) is DISCRETE DATA. Everything you hear in the real world is continuous over the time domain and no matter how advanced our recording technology is, you can never ever replicate the source 100%.
Put it this way... Have you heard a DW Neil Peart signature snare? A lot claim that it is the holy grail of DW snares. But do the present Rush recordings capture that? I don't think so. Now if you focus on capturing the snare drum alone, there will be other factors that you may not be able to capture perfectly, such as, how much attack does the snare produce? Timbre can easily be captured, but those transients of different degrees are pretty hard to replicate. That is why recordings just serve as a GUIDE to buying gear.
Back to hiyaw, Hiyaw can be recorded partially but it is not very appreciable. In fact, I can get an average-sounding guitar and cheat the recording process (maybe slap in a little compression and do some artificial chorusing and time delays) and claim it has hiyaw. And then, everyone will start buying into it. Bottomline is, the special properties of hiyaw can only be appreciable if you PLAY the guitar as opposed to being part of the audience.