Recently I have been choosing OSes to use on my MacBook Air 2009 Core 2 Duo 2.13ghz/2GB/Nvidia GeForce 9400m . The only choices I have are Yosemite/El Capitan due to my need for Office 2016. I've chosen El Capitan to install soon(unless Yosemite is better?). I've used El Capitan before though and it's not too impressive(not that I expect it to be, but it's really sluggish) which leads me to the question. Are there any optimizations I can do?