When it comes to finding the most comfortable acoustic guitar shape, it is always best to play the guitars rather than going by measurements found in the brand's catalog. From my experience, it is fair to say that more people prefer the dreadnought over the jumbo shape, which might have to do with the Jumbo's large dimensions. Dreadnoughts feel very balanced and comfortable to play, sitting down and standing up, but you should see which one feels the best to play.