Two more problems with YOSEMITE that upgraders should worry about...
#1... Still not fixed is the "PLUG IN IPHONE BLUETOOTH DEATH" bug.
Yes, plugging in your iPhone with any 3rd party iPhone cable will often wipe out your Bluetooth on your Mac forcing you to reboot. And yes, I reported this multiple times, but it's not easily reproduced. But it even happened once with the official Apple iPhone cable which I ALSO get the warning, "This is not a compatible iPhone product."
THIS IS A PROGRAM THAT APPLE NEEDS TO KILL ASAP. Even their own cables are being identified as 3rd party now and bricking your Mac, but it's far worse in Yosemite. Be prepared for lots of reboots if you have a wireless keyboard & mouse.
#2... Constant keychain password issues with MAIL and iCloud. I constantly get a password warning that iCloud cannot connect and that certain features are now disabled. MAIL won't get mail from my accounts. I keep checking the passwords in KeyChain Access and they're correct. My iTunes/iCloud password seems to work in iTunes. I can access my email accounts via the web, but MAIL WILL NOT REMEMBER THEM! This problem will drive you to a drinking habit!
Everyone here keeps whining about the whiners. Well I've been reporting this stuff since the very 1st BETA and still Apple hasn't fixed these things.
My advice on Yosemite, which I do like is, upgrade if you still have a fully working Mavericks partition. Otherwise WAIT!
----------
I think it's a good idea to run permissions after wards as well.
I do find Yosemite to be more stable than mavericks, even though it lags more. I'm going to increase my RAM to 8Gb, since my Mini is upgradeable.
See, Apple, THIS is why RAM should never be soldered on.
Bastards.
THANK YOU! This is why I lambasted Apple on soldering RAM.
Yosemite is just not going to run well in the long term with that disposable appliance. Sorry.