I have not read any of the replies/reactions to your post, so I am completely untainted by anyone else's comments.
People make mistakes The reaction to the mistake tells the story. In this case the shop owned up to it and wants to make it right, or so it seems. The liability is clearly NOT on the part of Taylor, so I would not judge them based on this. Unless this is the only shop in town, you obviously like dealing with them, being that you have purchased several guitars from them in the past. Personally, I would not make an emotional decision and take a knee-jerk reaction. They generously offered you a guitar to play while waiting for the mistake to be corrected, so they apparently appreciate your business. If it were me, I would go home, drink a little scotch, play one of my other guitars and get over it. Before you know it, the new guitar will arrive and this will be nothing more than a memory. You'll be making better memories with your new guitar soon enough. In other words, chill out. Be reasonable with them and in the end, they will treat you right and you will be happy. If you go in blazing mad about the whole episode, they will satisfy you begrudgingly, and probably won't be so happy to see you next time you stop by the shop. Remember the golden rule.
I recently brought a guitar into a shop to have a repair made (chip on the top). The repair, in my opinion was lousy. I tactfully and in a frienfly way let the owner of the shop know that I was not satisfied with the work, and he is going out of his way to make it right. In fact, this is motivating him to look into new products for repairing this kind of work and my guitar will be the test subject (It's a relatively inexpensive Epiphone, so I'm not too worried). This has been going on since March, and I suspect that it will stil be severla months before the work is done. And I suspect he's going to do the whole thing for free (althoug I would pay for his work). I thnk he's willing to go out of his way for me because through this whole ordeal I have been very reasonable, maybe even too reasonable. But in the end, I have a good sens that I will be happy with the work, plus I am not expecting miracles - just a better job than the first attempt.
So relax. Let them make it right and don't sweat the samll stuff. Enjoy your BTO when you get it and don't forget the pix. I wish I could get a BTO...
On the other hand, considering that the guitar was stunning, I might have considered negotiating with them and taking the guitar for a substantial discount and then having a nice fishman(or other) system installed (I'm not a huge fan of the ES).
Jim