OK. 2006 2GB iMac breaking down. I think I'm going to buy a MBair, 13inch. Will use it mainly for surfing the web, filing electronic bills with insurance companies (I'm a doctor) photo library (I have about 3000 photos now) and light word processing. No gaming, duh. Very confused though. Would someone explain 1. difference between 1.3 and 1.7 ghz 2. difference between 256 and 512 flash storage? 3. 4 or 8 GB I know this is boring to you MAC whizzes but sure would appreciate a nontechnical education. Thank you!