I have constant crashes/freezes when waking up on Yosemite, and something about having iCloud disabled makes every iLife application show unrelated dialogs (usually "This will overwrite the existing file on iCloud" warnings, despite the file not existing at all, nor having iCloud), the EULA box randomly shows up in System Preferences and gets stuck in an infinite loop of showing me the terms even when I press cancel, yada yada. I agree with the word "shoddy". I can work around all this, but it's like nobody bothered to test it. I'm part of the Appleseed program and send in every bug I find, but apparently they're all minor enough to not be patched. Frustrating.

I agree. The Mail client is constantly beach ballin and freezes at times. The issue is resolved by deleting the account and recreating it again. Surely not as intended. Especially for an app that virtually everyone on a Mac uses on a daily basis. I keep sending my crash reports but Mail client software updates seems to never come...

Also, another really annoying bug is when screensaver goes on and locks the screen. Sometimes, if I try and wake it up to fast it will freeze with a black screen for 60-120 seconds before I can unlock it again.

Hopping on this thread: Printer discovery - does it work anymore? I had to toggle wifi on and off on a 2014 Macbook to get it to work

I have to reboot mine...

Yup. The iconic lack of care on software side can be seen since forever when ejecting an usb. What used to become an eject icon with an eject label it's an eject icon with a trash label

That is just the smallest of thing, but is so easy to spot and fix and really his square against the level of detail the hardware side gets.