At Martin Music, I was able to hear sinker redwood on a number of GAs and GSs (both Taylor and R Taylor). Here's a quick review, and please keep in mind that it's all a matter of personal preference and the specific guitar played at the time:
1.Madagascar Rosewood: Fabulous, rich piano-like tone - beautiful balance. I played both R.Taylor and Taylor GS shapes. The R.Taylor was stunning, but the Taylor was less than inspiring.
2.Indian rosewood: a bit too dark, and somewhat muted (but I'm not a big rosewood fan to begin with). Two Taylor GAs, that both sounded sweet and resonant
3.Mahogany: mellow, but a bit too thin-sounding - a Taylor GA
4.Ovangkol: that perfect blend of bass, mids and highs - very complete tone! Two Taylors - one GS with an Adi top and a GA with a sinker top. While it was close, I preferred the sound of the sinker - wasn't as "dry" as the Adi, and had a bit more lushness to it.
All this "research" led to my choice of ovangkol as my personal best. Hope this helps!
