Well, there's certainly some issue that was between iOS 8 and iTunes. And the OS presumably has a lot to do with WiFi in general. It wasn't unreasonable to suspect that Apple engineers could fix WiFi syncing by fixing any one of the three.
But since we've had a few updates of iTunes, in two different versions, since the problem with WiFi syncing has been officially reported to Apple, I think it's safe to say iTunes can't solve the problem by itself. And Yosemite beta has been updated several times as well, so general WiFi fundamentals don't seem to be at fault. (Besides, WiFi in general has been fine on my iPhone 6.)
That leaves iOS 8.1 as the potential fix.
Other than WiFi syncing, I haven't had any problems with iOS 8. (Remember that lots of apps have to be updated for every iOS release.)
I'm still suspicious that the change of how MAC addresses were formed, a security measure, is at the heart of this issue.