Sup John,
I have a 33 year old Martin D28 and can't adress the sound of GPCP. But I did own a Taylor 214CE which I can attest to. I found that my 214 was too rich in treble. I was at a funeral one time and a guy was playing a 214CE through an amp. It sounded terrible. I immediately sold the Taylor. Now, some like all that treble, but as a bluegrass guy I like an even tone, bass, mids & treble. Granted, my Martin has a solid bass which rings out, but the mids and treble are pretty equal. Can't go wrong with a Martin in my humble opinion.