the difference between 21.600 low beat and 28.800 high beat you only can see it with a professional watchmaker time-leve machine.
there you see all datas which are adjustable with the movement.
and all gen swiss movement have always the regulator-needle.
only some asia movements have them not, because it is a cheap kind of movement production.
the chinese always think, when they can make upgrades then they earn more.
but with a good watchmaker with experience he can also adjust the regulator without the needle, but it needs more time.
not so exact like a regulator system with needle. but also here the watchmaker need time maybe two days.
included the accuracy between the different wearing habits of a watch on the wrist, then he need longer to get a good - super accuracy.
never with one time adjustment. never.
one of my last swiss movement in a pam, we needed one week.
that means, watchmaker adjustment in connection with the time-leve-machine. then one day to check on my wrist.
the day after a readjustment, and again and agin.
this pam with the swiss 7750 - 21.600 bph has a accuracy of 1,5 second per day plus. top result.
other pams from me with a swiss 7750 21.600bph movement have ca. 2 -3 second per day plus.
never possible with an asia movement. no matter which one.
material and finish and processing quality are too bad.
for me an asia movement in a pam is only a transitional phase till my watchmaker installed a swiss one.
for the handwind movements, i only have swiss unitas and some asia seagul unitas movements. the swiss once have 18.000 bph.
the seaguls have 21.600 bph.
i don't have swiss 6497-2 unitas movements. maybe later or not.
rolli