As a show of appreciation to all of your advice, I figured I'd post here what I finally settled on. Here's the list:
-Nikon D850
-Sigma ART lenses: 24mm f1.4, 50mm f1.4, 135mm f1.8
-Sigma USB Lens Dock
I've only started to do some casual shooting, so I can't give a thorough review of the kit yet. But so far, I am extremely happy with the setup. I've spent a lot of time learning all of the D850 features, custom settings, etc. I watched a bunch of youtube tutorials and
Steve Perry's youtube channel was the clear winner for me. He knows the nikon system inside out, and explains complicated concepts in a very intuitive and clear way. Highly recommended. One thing I was mildly dreading about going from Phase One to Nikon was Nikon's (or Canon) endless menu system. Yes, it is vast and overwhelming. However, Nikon has something really great called "My Menu", where you can create your own little menu with the features you frequently use, so you don't have to search for the feature you need when you need it. I assigned "My Menu" to one of the fn buttons for quick access, and it works brilliantly. Image quality of the D850 -IMO- equals or surpasses the P30+. Color rendering is so good, I barely have to do any adjustments at all in Capture One. The Sigma Art lenses. WOW. Thanks to a few here on LL who mentioned them when I was asking about the Zeiss Milvus as an alternative to the Nikkors! The Sigma Art is a joy to use. IQ is beautiful. Bokeh, sublime. AF, fast, near silent, and accurate. And now... the Sigma USB Dock. I must say, now that I've calibrated my lenses with it, I can't see why any AF user would not use this. I'd rather shoot MF than with a non-calibrated AF lens. Out of the box, my ART lenses focused -apparenlty- very well. After calibration, auto-focused images are razor sharp, precisely where I need them to be. The only downside to the dock is that it took me a while to figure out the calibration process. Sigma has a few instructional videos on youtube, but for someone who is new to calibrating lenses, it lacks instruction (or maybe I'm just not that smart). But once I got the hang of it, the results sliced through my eyeballs like a lightsaber on Tatooine. Highly recommended.
I first acquired the Phase One P30+ kit because at the time (+/- 10 years ago), it was the only camera that would give me the IQ for my subject matter. Now, the P30+ is still a magnificent piece of gear, but much too big, too heavy, not weather sealed, and too expensive to upgrade from. The D850 has the IQ, ergonomics, weather sealed, compact, and won't require a selling a kidney to upgrade. I'm so happy. My only "problem" now is that my camera bags (formally used for my Phase kit) are too big
Thanks again for all your advice!
