Can't agree here. The latest AOSP 4.4.2 base with F1 baseband is totally flawless on my T5, way better than stock. Super fast, no bugs at all, excellent battery life and much more functionality right as it is, no need for painful modding of the UI and framework.
Maybe it actually is due to the small hardware differences we seem to have across our devices. Camera and radio modules are obviously several different versions, we have a magnetic sensor whereas A116 doesn't, who knows what else differs in detail? That's the only rational explanation I can come up with on why some of us face issues on 4.4.2 while others have none at all.
Before hyperion built this AOSP I also tried a few A116 custom ROMs on my device, and the results were somewhat similar to what you guys get on 4.4.2 - loss of signal, fast draining battery, cameras not working, random reboots etc.