edit: wiredfool pointed this out above, as I was writing this. Having purchased 2 equally specked computers at the same time and experiencing differing results. After upgrading from MAvericks, I personally experienced significantly better battery life. I have edited launch daemons and blocked some outgoing connections which caused coreaudiod to go into an infinite loop using >80% of the cpu. This KILLED my battery and performance. After fixing this issue, both of those metrics were amazing.
https://medium.com/@mariociabarra/wifried-ios-8-wifi-perform...
I have gamecenter.app deleted, airdrop and bluetooth disabled and many of the sharing and push notification services are disabled. I have fairly decent connectivity and not much seems to change after disabling awdl0, a speedtest seems pretty similar.
I am now really interested. Is there a way I can run a better speedtest, and also check if these issues you describe are happening because it sounds as if it is sporadic. Also, is there a way to use something other than bonjour/mdnsresponder via wi-fi? I could not find anything which is why I still use it unfortunately.
edit: Also, almost forgot.
> This was a bug for which we know the root cause and for which a patch was actually developed.
What? I have seen issues surrounding coreaudiod but none of them are referenced in your post. The post actually explained the iOS connectivity issues I am having but doesn't seem related to a glitch in the core services daemon, which seems to affect some users, and was almost certainly self-inflicted. Now, I want to test my connectivity to confirm, but it seems alright most of the time.
It seems obvious to me that a technical review will be pretty limited in term of "stability" evaluation. They will run a few tests, but it can't cover all the configurations. Especially things like the wifi issue which were mostly triggered depending on the network environment (what is your access point? What other devices are connected? etc.)