I hope the Yosemite upgrade goes well, but I will be waiting on the sidelines to see how it goes. I still have issues with Logitech mice and keyboards on Mavericks because Logitech never got the drivers sorted out. I like the way Mavericks works, so there isn't much incentive to upgrade unless iOS 8 and Yosemite actually work well with each other and share information in a usable manner. I'm hoping they can get the Mail app to finally work well in Yosemite, but I'm not holding my breath.