I think that all Taylors have X bracing. Later models were revoiced with slight shape modifications. The relief routing goes around the inside surface of the top, which theoretically allows the top to move and vibrate more. CV bracing is the newest feature offered on higher priced models and BTOs. Since I own several different GAs of varying ages, I have personally experienced all these features. All I can tell you is that the older guitars sound great because they're older and the newer ones sound great because Taylor has advanced the science of consistent tonal performance. They're all different, but they all sound great! I suppose it's a matter of personal preference, but I've heard some CV braced guitars that didn't do it for me, while others (like my 2011 BTO) sound suprisingly mature right out of the box. Still,there are too many variables (wood, age and other factors) to allow a conclusion that one is better than another. Hope this helps.
