Public Beta 5 is out too.
After testing Yosemite for over 2 months, here's what's DOA about it so far...
#1 First off and this is embarrassing for Apple, but the Feedback program while collecting data from your computer disables your ethernet internet! I've complained since day 1. They never fixed it. Reported since BETA 1.
#2 Plugging in any iPhone, at least since IOS 8 (or the latest 8), disables your bluetooth completely, meaning goodbye Magic Mouse, goodbye wireless keyboard. Seems to only happen when the iPhone is completely charged. But only solution is a re-boot or standby peripherals. COMPLETELY UNACCEPTABLE.
#3 No clue as to whether this is related to #2, but constant warnings that Apple iPhone peripheral is not compatible with this phone. Doesn't matter if it's Apple's cable or not. iPhone is then not recognized and Image Capture program fails to work and charging stops. Tested with several iPhones, same result.
#3 No sound on SOUND keys as in you can't tell how loud you're increasing the volume from the keys. Also sound to send mail is so quiet, you'll never know if you sent the mail or not. Reported since BETA 1.
#4 Displays issues. No matter how many times you change it, Displays will not boot to the correct display you've set. For people with multiple displays, this means turning on another display or in my case having to switch to an HDTV to boot up and log in. COMPLETELY UNACCEPTABLE! And I've reported this since BETA 1 too.
#5 Some Mac OSX partitions are no longer compatible with disk repair software, so be careful. You'll get a warning that your disk mapping on a drive is no longer compatible.
#6 There is no indication as to when Spotlight is indexing. That's very annoying since normally you'd wait until indexing stops to use a Mac because of the slowdown.
#7 Preview loads for no apparent reason when an iPhone is connected. No clue why.
Yosemite is NOT READY FOR PRIMETIME in my opinion after 2 months of frustration. I feel like Apple owes me money. Oh, I should add, the installation corrupted my Mavericks installation too causing all Mail accounts there to be corrupted, but I can't say that's related to Yosemite except that it doesn't like other Mac OS X partitions. None of the above problems happened in Mavericks.