Fom my experiences:
fresh from the service it keeps + 1,5 sec a day time, which is amazing like a grande comp for an ultra thin movement with a beat ratio of 21.600 only and a small balance!
If you waer it daily for 2 years it starts to gain more and more until it gaines 15+ sec and more, but as we all love it: it is good enough.
Being unidirectional the winding efficiency is pretty impressive and reliable.
On top of all it is also one of the best looking/designed movements.
ALL Pateks should be equiped with it
.
Great post
Moritz