Looking at the base 13" macbook air and the 13" macbook pro retina. I like the lightweight and long battery life of the AIR but the retina pro is more powerfull. My current macbook has a 2.4 ghz intel core 2 duo 4gb 1067 mhz ddr3. I see the AIR has less GHZ. will I notice the difference. Most of my work is word processing and internet including streaming videos. NO GAMES