If the B-42 had the seconds increments on the seconds subdial, then no question the Fortis, so I voted for the Sinn, not out of derision, rather as this is an exceptionally useful feature for a chrono, imho for splits and comparison timings-and looks better, imho too :)
I like the styling of the Fortis quite a bit more.
Best wishes and good luck,
AP. :)