The newest major release of OS X has been out now for three months. Although it contains many new features and general improvements one needs a high frustration tolerance.
Apple has actually managed to destroy basic functionality which used to work flawlessly for many years. Particularly annoying is that they published the OS in this shaky state – I bet they were aware of the many faults.
My Top 7 of the most annoying errors and changes:
The sleep mode has become practically unusable, because my computer now wakes up every second hour thanks to "Wake reason: RTC (alarm)". Of course, all the HD drives also spin up, which is certainly not too healthy for them. Changing the energy savings options has no influence, the problem seems to be caused by the replacement of mDNSResponder by discoveryd.
Update 31.01.2015: This seems to be solved now with OS X 10.10.2. Finally!
External hard drives, which are connected via FireWire, won't shut down anymore. This "feature" got introduced with OS X Mavericks, yet still exists in Yosemite and will probably not even get fixed anymore. Apple apparently has gone the path of least resistance here and circumvented problems with hibernation simply by not letting FireWire drives sleep at all.
- The Apple earpod remote no longer works. Previously it was possible to control the Mac using the remote control built into the Apple headphones, and – for example – adjust the volume or select the next track in iTunes. Even the microphone is no longer recognized by the system.
- My Macs are not quite up to date, the oldest one (iMac) is even from 2007. On the one hand it's great that Yosemite still can be used on machines of that age. On the other hand, the GUI – particularly in Mission Control – became insanely laggy. Even though the animations and all that stuff still look the same like in Mavericks.
- Bluetooth does not work anymore satisfactorily. While I can still connect my BT headset, the audio transfer gets interrupted often or stops completely.
In my opinion, the system font is difficult to read. Add to that an apparent bug in font rendering, which makes the antialiasing go crazy and text look like viewed through a smeared plate.
Spotlight has become chatty and now sends a lot of data over the net by default.