I've been using Mac OX 10.10 El Capitan for a few days now, and it's been fairly solid for me. I've encountered some minor bugs, but overall it's a solid point-oh release.
One new feature that I'm not too fond of, however, is the new "shake to find your cursor" thing. I really don't know why it bugs me, but it does. So I went looking for a way to disable it.
The solution is pretty simple. Run the following command in Terminal, and reboot your machine.
defaults write ~/Library/Preferences/.GlobalPreferences CGDisableCursorLocationMagnification -bool YES