I'm thinking of picking up a new 12-string to be used only for recording and have narrowed the search to a taylor with mahogany back and sides: mahogany was recommended for recording 12-strings, and taylor was recommended for playability for old hands like mine. These are the 300 and 500 series. There aren't any in the stores locally, so I have to buy one without a listen. Is there any serious sound difference between the 300 and 500 series, or is the difference cosmetic?