So, I had a previous post about my 2011 13" max'ed out MBA having all kinds of beachball issues, etc. and just general discontent with Apple product reliability. I fresh-installed Yosemite and am in the process of reinstalling apps. When downloading all of my OneDrive and DropBox folders, the MBA is shutting down every 45 minutes due to heat. The fan goes nuts for about 10 minutes, and then the MBA just shuts down and won't restart for another 10 minutes. I'm trying to stay in the MBA family, but this is beyond irritating. This thing can't handle syncing files?? Or maybe Apple has activated the level 2 MBA "upgrade button" they have in the basement at Cupertino?