Recently acquired guitar custom built for original owner 10 years ago, and then 2 more owners. Deep body 000, mahogany B&S, Adi braced with Adi top, forward shifted X tapered braces. Seems scalloped bracing is much more common/popular, so curious why one would choose tapered?

Appreciate learning more about these incredible boxes with wires!  Thank you :nana_guitar

Just one of the methods to adjust the flex and response of the soundboard or back to achieve a desired sound.  Brace scallops, pattern, locations, material and number are other variables along with top/back size, shape, and thickness.

As a buyer, it doesn't matter. It matters to the builder as it's part of what they use to make the balance. Scalloped and tapered do the same thing, just a little differently. And, in life, I've learned to never mistake popularity for quality.   

Classical guitar building has evolved far more than acoustic building and, if you like the subject of bracing, you might want to do some reading on those bracing systems. The much more important factor is where you put the braces and, outside of Larrivee and a few others, acoustics have been pretty boring as far as braces go. The difference between scalloped and tapered can be negated by so many other things so it's important not to give them much weight unless you're the builder.

Pilgrim - well, the flex is certainly working on this one based on the back & neck vibrations.

Bowie, interesting you mention Larrivee because this is an Ed Bond build.

And will do some exploring in the classical bracing rabbit hole....

I love lattice bracing on a classical guitar. Even on a factory guitar like a Cordoba you can hear the superior sound difference on the C-12 (lattice) vs the C-10. Sadly, Cordoba doesn't make the C-12 left-handed. And the classical double top instruments sound great also. I owned an Eastman double top OM. What a dud, however. It was as powerful as my Eastman 00-20 with an Adi top. And I was watching a video demo of the Martin D-15. The reviewer pointed out that on this instrument, Martin only utilizes one tone bar to allow more vibration of the top. I've always thought based on demos that the Martin D-15 set the standard for dreadnought hogs.