Well it's true you can't get all the nuances of tone, etc., with a rack, but there are players who can really do a good job (Dylan ain't one of 'em). One thing to address is, especially if you're playing guitar as well as rack harmonica, is that many harps are not tuned to the equal temperament that most tuners provide for the guitar, so you may well be distressingly out of tune with the guitar. If you want to be in tune, avoid all Hohners (with the exception of Golden Melodies), and plump for Suzuki or Lee Oskar harps. They come ready-tuned to ET.