Based on my experience of using Yosemite. It has been a really good OS. I like the tonne of new features that it has. All of them works great. I use spotlight 90% of the time on my MacBook Pro. As i said before, I love every feature of Yosemite and i still kinda miss Mavericks (OS X 10.9) but i am satisfied with what Apple has done with Yosemite and I can't wait for the new OS X 10.11 to be finally released on WWDC in less than 6 days.