is there any benchmark test that compares this two Models?
Is this better CPU a big advantage, when im using the macbook for some raw-photo developing?
Thank you for your help!
TL;DR: What I assume to be the new processors in the rMB are considerably more powerful, and the top end M7 is comparable with the i5 CPU in the MacBook Air. Regardless, if you're seriously contemplating photo development, I'd suggest a 13" rMBP at a minimum -- preferably the 15" rMBP, as that's guaranteed to handle anything you can throw at it.
Hope this helps.