Bumping along with the 344 bumper movement from 1954.
Coaxial?
We ain't got no coaxial!
We don't need no coaxial!
I don't have to show you any stinking coaxial!
I totally agree! My 32 year old Speedmaster 345.0808 with the calibre 863 movement runs consistently -1 second per day since I serviced it six months ago. Worn 24/7 with the chronograph running. Is co-axial really an improvement?