Martins and Taylors are both good, mass produced guitars, depending on the model you choose; however, there are serious advantages to visiting a Luthier and having a guitar built to your specifications. There are dozens of these small operations around, and it's worth asking around on the various forums for a recommendation. If you are in the UK, the names Northworthy, Lowden, Fylde and(especially) Rob Armstrong spring to mind. I asked Rob about the difference between buying a Taylor and buying one of his custom guitars; his reply was that if you went to the Taylor factory it's unlikely that they will stop production, make you a cup of tea, give you several guitars to try, listen to how you play, measure your hands, talk for a couple of hours about the sort of guitar you really want, and then build exactly that. The prices, by the way, are about the same...
Tim from Bit on the Side