Fair point. OSX has always been heavy on the overheads- a quick look at the Geekbench browser for my processor (4770K) brings that home
I think OSX Nebula users are looking for performance that is less 'spiky'- a problem with the AAX versions and the main limit on the number of instances that can be achieved. AAX Acqua plugins suffer particularly badly in this respect.
The best performance I can achieve in PT12.4 is by running VST Nebula instances inside BC Patchwork or, more recently, Nyrv Agent. Minimal spiking and I can load it up to the point that the graphics are slowing down!
Enrique, you mentioned in another thread that an AAX update was near. How's that looking?