Hi my buddy would like to know if he should keep his Mac Book Pro 15", 2.2ghz i7 with 8gb RAM, 120gb OWC Mercury Extreme SSD with 500mb hard drive now that there is an Air available with 1.7GHz dual-core Intel Core i5 processor. He just got the 15" last week. He would like to know how close the performance of the Air is to the MBP because he has to carry the 15" from home to work via subway. He needs to use SAS Business Analytics software in a Windows enviroment(using Parallels) and runs calculations about 50-100 times a day. I think each calculation takes about 2-5 minutes on the MBP. I heard the new Airs are much faster than previous models. I just want to give him a percentage difference in performance so he can literally weigh his options. If the performance is close he might return the 15".