Hey Rykoshet,
Danny Gatton, and Roy Nichols used to use picks like that, but I don't think they were called jazzIII picks back then. If you like the thickness, but don't really care for the size try a bigger pick with the same thickness. Jim Dunlop has a wide variety of picks, so I'm sure you could find something more to your liking.

Hey robm06,
Like most everyone has said, it really depends on what you're doing. I play many styles, and there are a few of them where I would be lost without a pick. Let us know what you want to get into, and perhaps we can give you more input on this.