As many know, the IQ4 is unable to report the zoom settings for either the Schneider 40-80 and or the 75-150. This is a bit surprising to me. In the meta you get the fact that your lens is the 40-80 etc and shutter speed. Hopefully this will not require sending in two 8K lenses to have their firmware updated, and can be handled in a firmware update to the back.
As for the ES and tech camera use, the fact that you no longer have to take the dark frame is a huge improvement. In many articles written on the IQ3/ES and tech camera use it's mentioned that you will need to take a mandatory dark frame, then you should be able to continue to use the ES without taking another. In fact, I found that with even a 1/3 change in shutter speed, the back would call for a dark frame. So net each time you changed the shutter speed via ES, you had to do the dark frame. May not sound like much but if you are using a filter stack, like Lee, or Wine Country, where you are not able to get a totally dark frame unless you pull off the filter array, it was a pain.
I would also like to see P1 figure out a way to allow the photographer to input the F stop with ES into the meta. As has been pointed out, currently the back just remembers the last setting if on the XF, and continues to record that to the meta. Odds are you will not remember a year later that you were actually at F8 during that shoot, not F 12.
I guess I am also the only person using this back that feels the Live View is not the same as Live View from the IQ3 or even IQ250. The Live view from the older backs, showed a much more contrasted image, with a bit more micro detail, which for me made manual focus much easier. The Live View on the IQ4 is flat, and have almost no contrast and makes viewing the image at 100% more difficult, again for me. I did find that by turning off focus peaking, the Live View does gain a bit more contrast and allows for easier Manual focus.
Peaking is green, again, why? Most cameras use White or red, would prefer more color options. Phase seems stuck on green back from Focus mask.
The issue with Live View and exposures longer than 1 second is clearly documented by CI in their blog and even P1 in the manual. Hopefully P1 will get the older style Live View back sooner than later, as working in low light with the current solution is taxing.
Paul C