Many years ago I heard about a little demonstration that was held in a New York music store (possibly Matty Umanov's) A number of players and listeners gathered and allowed themselves to be blindfolded. They then played on, and listened to several guitars, including Martins, gibsons, Guilds, and some less expensive ones. The winner? An off the rack Yamaha!
The old Martins just seem to have class. On the other hand I wouldn't kick one of those pretty Collings, or Santa Cruz numbers out of bed.