Haha I myself downgraded my moto g2 to KitKat from Lollipop and don't regret it at all... After downgrading I placed a colleague's moto g2 which runs lollipop next to mine and the fact that KitKat was faster was undeniably evident.
You could flash a custom recovery to stop the update notification
I downgraded to Kitkat after the Lollipop update using the tutorial at the top of this forum when it was first posted. The phone nagged me for awhile about new firmware available and I'd have to hit postpone once a day and then it eventually quit bothering me. I do remember turning off Auto Update at some point but I don't remember if this immediately fixed it.
Options>System Update and then uncheck Auto Update and then after maybe clear the cache and reboot the phone? Sprint, USA.
My phone hasn't checked for an auto update since 03-25-2014 since I changed the setting.
If it doesn't work then hitting the postpone button once a day, I don't remember that being too much of a nuisance at the price of to be able avoid Lollipop until they improve it. I just got used to it.