Just to pick up on the "rigorously acoustic" stipulation.

Whilst it is true that peizos and transducers pick up the vibration of the strings prior to them making a sound we hear, and yes, humbuckers don't even include the saddle in their pick up, there are plenty of in guitar microphone combinations that are like a microphone away from the guitar but closer, the argument of acoustic being therefore moot. LR Baggs make an excellent one called Lyric that I use in a guitar I had made to my spec' so didn't want to lose the effects of my chosen tone woods.

Most top end in guitar systems combine microphone with transducers and piezo and allow you to blend between them to achieve the best amplification of the acoustic qualities of the guitar.

In concert, it's the sound your audience hear. I personally prefer the reassurance of consistency, ease of sound check and minimise risk of feedback. (I always fit a cover over the sound hole.)