They are "slightly" better on the Pro, but don't expect bass, midrange depth or anything less than "tinny" on either. I came from a Macbook last year to a MacBook Air, to the new Alum. Macbook 2.4 and the new one is the best of the bunch. Some Windoze laptop computers have 5.1 sound, and sub woofers - (when they work). But, that's why we use Macs, and have Bose (and other) external speakers when needed!!😀
For the size and weight difference, I choose the 13" Macbook over the Pro.