Last week I got the "Over The Air" update to Android 5.0 on my Samsung Galaxy S5.
A download of 924 MB (rounded down). 3 GB of storage necessary to install.
I had to uninstall Goat Simulator to upgrade the OS, and then spent half an hour disabling apps I had disabled in KitKat before the upgrade. To summarise: the OS upgrade was a pain in the goat horns.
The good thing is that I am enjoying Lollipop on the S5, mostly because I am runnning the Google Launcher and using all Google apps.