I have had several issues with Xcode 6.0.1 that don't occur in Xcode 5. But none with Yosemite itself. So I just keep Xcode 5 installed and use that whenever I encounter a problem.
I didn't noticed any issues regarding IOS development. Everything works smoothly. I keep my git repos on my Time Capsule, I had issues connecting to the drive a few times (never happened with Maverick). I had to restart to solve the problem.
Thanks for the reduce transparency tip! that one really helped! Was feeling Windows Vista all over.
What bugs me more than anything is the full screen on zoom button. Probably a nice feature on laptops but I've a dual head setup so now whenever you just want to maximize some window one of your displays just goes dark - wft!?!
I've since bitten the bullet and also upgraded to Yosemite. I haven't noticed any major issues either. As dantastic has mentioned, the lack of a maximize option will take some getting used to. I liked having the menu bar but I suspect I will discover I don't use it nearly as much as I thought I did. The other issue I found with full-screen mode is switching between the project window and documentation. Can no longer use Cmd-` when full-screening.
Well aware of the option click for the old functionality. The point is, with my setup I will _never_ use full screen mode so I would prefer to have the option to configure the feature.
i get weird errors trying to compile apple's metal demo codes, they don't compile even with my iPad connected. it can't find its own binary files, include files, doesn't link