Hi all, I am looking to purchase a used MacBook Air and was wondering if there are any specific versions or configurations to be avoided. I remember reading on this forum some time ago that the first generation had issues with overheating which subsequently throttled down the CPU speed, and wanted to know if this was also an issue with later versions of the Air in addition. Also is there any real speed increase in day-to-day apps from the basic 1.6 CPU to the higher 1.8 or the newer 2.13GHz series. Any information/responses appreciated. Thanks.