So I got a brand new factory-fresh Sinn 104 on Monday and I have been timing it on WatchCheck for the past few days. It's running at +11 secs a day on average with full to near-full wind..
For a movement that is meant to be a Top grade SW200-1, Sellita specifies their average rate for this movement at -/+ 4 seconds a day, which is what I expected.
I know some of you will say "give it time to break in" but to be honest, I've owned a dozen automatics and the general rate I get a few days out of the box is the rate they stay at. Never had a watch that "broke in" and if watches did have to break in, then that would essentially destroy the COSC system (so I take it to be a fiction or so insignificant as to not have an effect on a watch's out of the box, full-wind accuracy).