Any updated iOS is horrible on previous devices, that’s always been the truth, apple has never concerned itself on the mobile device front anyway, ensuring that OS upgrades run reliably on anything less than 1-2 generations prior. If you are more than 2 generations out of date, they expect you to upgrade, period.
The only exception might be the iPad2 which they still sell, but that’s mainly due to its footprint in certain verticals, and frankly I really wouldn’t want to think how IOS 8 runs on that old hardware, sure its a dog.
Actually.... I upgraded my wife’s ipad2 to 8.1.2 last week. It works fine. No noticeable difference in performance etc.