I have the base model and just went on vacation during which i had to start editing a 135,000 word document in MS yWORD 2011. The mba worked beautifully. Never once heated, never heard the fan. And it is so quick. Had all the document files on a very tiny usb thumb drive (sticks out a half inch) that i moved over to the mba. This machine is a dream. I may exchange it for an 8gb if i can just to future proof it.