No, not that Yosemite. Apple OS X Yosemite. Today was an epic failure. I tried installing it on my Mountain Lion 2011 Macbook Pro. The machine is a little older but is still very serviceable. It does have 16GB ram and 1.5 TB SSD and a quad core i7. Being a developer, I like connectivity. I have a 30" 2560x1440 monitor and a 1080x1920 second external monitor attached via usb 3 thunderbolt dock. The dock also contains ports for external hard drives.
I would expect at least some internal Apple developers to have a similar setup so that OS updates would support these devices. I couldn't be more wrong. After updating, I realizes that not all of my software work as expected.
First, though is that my 1080x1920 monitor didn't work because there wasn't a driver. Second, the wired network also failed to connect. Plugging network into the native port seemed to address the issue except that for some reason the dns servers were not picked up from the dhcp server. Wifi worked but I'd rather be connect via a cable because it is faster.
Various software either required additional downloads or didn't automatically start on boot. But ultimately when I installed the Yosemite driver for the monitor, the machine wouldn't boot. Luckily, I had my previous install image on hand to recover. I am going to revert my OS. There are just too many roadblocks for my taste. In the morning, my bootup disk will have a clone of the backup's OS.