I have a 13" 2010 MBA (1.86/4GB/128GB). The machine is starting to show its age. Everything has slowed down a bit. Start up, shut down, opening apps etc. all take a few extra seconds. I hardly ever saw any beach balls on it for 3 years, but now I am seeing it almost everyday doing routine tasks. Any thoughts on how I can breath some life into this machine? It still does everything I want it to (basically web browsing and MS Office applications), but it sure could use a speed boost. I have about 20GB of free space on the SSD. Would a clean install of Yosemite help?