I'm still on 8.0 on the 6 Plus and I'm patiently waiting for 8.1. The only issue I have right now with either 8.0 or 8.0.2 is the stacks+backboardd issue (even after getting a replacement). I heard that 8.1 fixes this issue so I'm patiently waiting.
yeah 8.0 is pretty smooth for me. at least as smooth as iOS 7.1.2 jailbroken was on my iP5. I plan on staying where im at until 8.1, or even longer than that as long as there is nothing major in the updates.