Just received a used 11" Macbook Air from Amazon (Mid 2014, 1.4 i5, 4GB, 256 SSD for $650) and it has Mavericks installed on it. Every other device I have is up to date with Yosemite and the newest version of iOS and they all interact well with one another. My question being, should I upgrade the Air to Yosemite or should I just do a fresh install of Mavericks on it? Seeing as it only has the 4GB of RAM I wasn't sure if Yosemite would severely slow it down. I would be using it mostly for web browsing, note taking, watching videos etc. as I have a very capable 15" rMBP already that I use for FCPX, After Effects, Photoshop, Lightroom etc. Also, if I were to attempt to use any of the previously mentioned heavier apps, would those see a difference in performance between Mavericks and Yosemite? Thanks.