I own several Martins as well as several Taylors, including both the GPCPA1 and the 814CE. When I bought the Martin, I actually went to the guitar shop to buy the Taylor; my friend had one and I liked it. When I was at the shop playing the Taylor 814CE, the shop owner hande3d me the Martin to try. I played both of them for almost 8 hours!
Both guitars sounded great unplugged, with the Martin being a bit more balanced across the full register, versus the Taylor which gave me more midrange. The Martin did not play stiffly, like my Martin D-45, the neck was really comfortable, and it was really pretty with the vertical MARTIN abalone logo on the headstock. Both guitars were exactly the same price.
Pluggedf in, however, was where we separated the men from the boys. The Martin electronics were far superior. With a built-in tuner and 3 notch filters that killed feedback, this guitar contained the sonic images of the worlds 10 best microphones. The Taylor had none of that and the ES system tended to feed back a lot.
While I was there, the Taylor rep happened to come in. To make a long story short, the rep said to me, "Bob Taylor promises that this guitar will sound just as good 20 years from now as it does today." Conversely, I am already familiar with how the sound of a Martin opens up over time, and I would expect a good guitar to sound BETTER 20 years from now. The other thing I didnt like about the Taylor is that plugged in, the sound was colored...kind of like playing the neck pickup of an electric guitar with the tone zeroed out.
Anyway, I bought the Martin and have never regretted my decision.
About 5 years ago, I saw the Taylor in a guitar shop, in mint condition, for just under $2000. I bought it and I still have it. However, I cannot play gigs with it because of the sound is too colored. So I keep it hanging on the wall in my guitar vault/studio for others to play during spontaneous jam sessions.
As I mentioned, I also own a Martin D-45...a $10,000 custom shop Martin that used to belong to Neil Young. It sounds great, but it doesnt play nearly as well as the GPCPA1. I also own a Taylor, limited edition PS14CE-FLTD in Sinker Redwood and Macasar Ebony. That guitar plays like a dream and is the sweetest sounding guitar I have ever heard. So, it isnt a Taylor vs Martin preference, it comes down to craftsmanship.
Between the 814CE and the GPCPA1, I wholeheartedly recommend the Martin. Sorry Bob.