John Poole, founder of Primate Labs:
So what 13-inch MacBook model would I recommend? If you can afford it, I think the 13 ? MacBook Pro Retina is the way to go. It?s as fast as the 13 ? MacBook Pro but lighter and has a much nicer display. If you're tight, the 13 ? MacBook Air, although slower, is also a great laptop.
The following is the updated Geekbench table comparing the performance results of all current MacBooks (Air / Pro). Since his tests are mainly based on processor and memory, the performance difference between HDDs and SSDs is not noticeable. (Primate Labs)