Keith - I learned more today. I can shoot in x3f format and export as an S-HI resolution jpg in SPP6. So I don't need to limit myself to shooting in the S-HI jpg format without a RAW file. I will try DNG tomorrow. I am getting more accustomed to the controls now.
The colors and dynamic range appear to exceed those of the SD1m but I won't do direct comparison testing until the weekend.
This will be heresy but I prefer the images on this new Sigma camera to those from the Sony A7rii. I can't explain it but the Sony photos appear to have no soul compared to what I get on the new Sigma. Of course, this is just a matter of personal taste and I know I am severely limited to low ISO and slow operation on the Sigma all the way around. But I am in no hurry. I can't wait to take this Sigma to Yosemite National Park in July.
Eager to hear your thoughts when yours arrives.