I always thought the Acoustic Series (GA, GC, DN...) guitars had a thinner top. I have played a GC3 and a 312-CE and thought the GC3 had a better sound. Of course, each guitar will sound different, or I could have been imagining the difference. But I heard it on more than one visit to that store. I don't know if the top on the current 314 is the same as the GA3. Yes the appointments are different, but I guess there is a chance the build of the guitars is different as well. That being said, I will be receiving a 2009 GA3-E by UPS closer to the end of the week. I patiently waited a long time for this one to come up at a price I was willing to pay (about six months). I am a believer in the Acoustic Series difference, and I hope Taylor continues to have that subtle difference in the new non-CE guitars.
Full disclosure: I also LOVE the Expression System, so by many standards, my ears may be flawed.