I think something about the way graphene emulates google play services stuff introduces a ton of latency. The same phone is buttery smooth on calyx, but so so bad on graphene. There were lots of other weird little UI bugs too, just things not working as expected. 

 It's because graphene has a lot of security stuff and calix don't.
Calix is less secure than stock android specially if you still use gapps 

 I figured it was probably to do with the security layer. Less secure you say, in what way? 

 If you install gapps it will be system applications in calyx
They also failed to deliver security updates a lot of times, sometimes for months 

 😬