Are you sure? Where do you think the S1R mkII is lacking?
Since I'm not an experienced/pro sports photographer, no, I'm not sure. But from what I can tell, a pro-level sports body would have the following above & beyond the S1RII:
- A stacked sensor;
- A bigger buffer with improved buffer clearing logic;
- A bigger body & battery, or two batteries (i.e., integrated grip)
- Possibly incrementally better AF (yet to be determined).
Not that you couldn't do amazing sports photography with the S1RII, but I suspect a true professional sports photographer would pass on it if they were looking for a new system right now. And I'm pretty sure Panasonic would not claim to have targeted such photographers with the S1RII.
BTW, at the end of Gerald Undone's S1RII video, he basically said that with a stacked sensor, the S1RII would have ruled the market (although I do think the other points I make are important for pro sports). Maybe they will make an S0 some day, LOL.
It's an amazing camera, but the choice to go with a BSI sensor has implications. Probably unimportant for most, but not everyone.
I'm certainly not canceling my order.