Aus.
Firstly, I do not own auto watches for ultimate accuracy.
We have atomic clocks for that.
😀
Ime, each Manufacturer should quote their accuracy for any given calibre.
For example. My Breitling, being a Chronograph, was rated by Breitling as not gaining or lossing more than 5 mins a month.
After the first service, the watch was gaining more than this.
I returned it to my jeweller, explained that the watch was out of spec according to Brietling’s own literature, and Breitling duely corrected this, FoC.
The movement in my De Ville is rated as a Chronometer.
I forget the exact accuracy as quoted by Omega, but have the feeling that it is losing / gaining seconds a week, rather than upto 1 in 15 sec, as the breitling would.
As you will know, this is the principle reason for the price difference between Chronographs and meters.
I’m seriously contemplating a Jeager Le Coultre reverso.
Lady luck is about to ride into town and I have wanted a reverso for a long time.
Jaeger are again, slightly unique, quoting their calibres by their own 1000 hour standard.
Basically, do some research into the calibre you want and ascertain its rated accuracy.
Also get some idea of servicing costs, if that is a consideration for you in the future.