Had it for a couple of months...
Great file quality, resolution as good or better than my IQ180. Compared to BW converted files from my IQ180, the tonality/transitions were smoother, specular highlights handled much better as well.
With B+W 486 filters, has a great BW look. Without any filters, has an etheral feel that is hard to replicate elsewhere. With IR filters, works well as an IR camera.
Base ISO of 200 makes the DF very versatile as a hand-held camera.
BUT....Phase forgot to mention that there is no LV on this DB. So on a tech cam, and even on the DF, anything off the visible spectrum is a challenge to focus. On my Arca, it was a hit and miss in IR as the charts needs an offset, but this is not consistent. It depends on subject distance. With the DF, if using IR filters, little light passes to the VF, so manual focus is not really an option. So, on-sensor focussing is a must.
I was back an forth with Phase on this, and of course, none of the literature said LV was not available. I had to open a trouble ticket to find out, and the best I got was "oops" we forgot because one of our product management guys did not mention it. They later said they may have some form of LV via an iPad working in "about" 6 months. Onback LV was not likely an option. Based on the USB availability, I was not particularly inclined to buy into any date commitments.
Needless to say, I was not pleased, and after much thought, returned it. Still think the files were quite unique though. PM me if you'd like more info.