Impressions so far:
- it's now the ugliest UI I have the displeasure of having to use; previously this dubious distinction was OpenSuSE's KDE, but now that is markedly prettier than OSX; Ubuntu, Windows etc are miles ahead, although Microsoft also worked hard at uglifying their own, since version 8.
- the dark mode is unusable, since it makes most of the mini-icons in the top menu black-on-black, i.e. invisible; and some are really useful, like, my OpenVPN icon.
- choice of two colour themes: rat grey with eye-searing blue buttons, alternatively a uniform rat gray; choosing the uniform rat grey (the blue is frankly insulting) unfortunately makes all the window maximise/minimise/close buttons grey, so I cannot tell or guess what they do just by looking at them
- they did away with the easily accessible full screen window corner icon, now the functionality is in the tiny "maximise" button, on the other side. Shifting the controls around keeps the users on their toes and the Alzheimer's at bay!
- the "taskbar" is now 2D, otherwise unchanged; still as crap as before
- "spotlight" now is an intrusive (but very rat grey) dialog box, of fixed size (thus much smaller than the previous menu), which requires me to scroll its scroll bar to look at results. Why do it with fewer moves when you can do it with more? As a bonus, it sends what you type to Bing, by default.
Absolutely no improvements detected so far, it's a solid downgrade. The only extra feature I found was iCloud in Finder, which I do not use or need.
Also, Yosemite froze my laptop the day it installed itself, in the login screen. This is a Mavericks bug that appears to be back, which I find utterly incredible.
I'm really glad I didn't pay money for this.
Overall: not recommended, particularly if you liked the remnants of the aqua interface, which now are fully gone.
