Dpreview published the full Panasonic S1R review:

The Panasonic Lumix DC-S1R is an impressively well-built full-frame mirrorless camera with lots of resolution, well thought-out controls and ergonomics and competitive video quality. Unfortunately its burst shooting speeds are simply outdone by the competition and for less money, and it falls slightly behind in overall image quality and autofocus performance as well. But the fact remains that the S1R is enjoyable to use and is worth a look for those that want a well-rounded high-resolution professional camera.

Links:
Panasonic S1R at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic S1 at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic 50mm f/1.4 S at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic 24-105mm f/4.0 S at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic 70-200mm f/4.0 S at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.

LensProToGo:

In this video, we cover Panasonic’s two new cameras the S1 and S1R going through some tests in the studio looking at High ISO or Low Light performance as well as exposure recovery testing both the HEVC h.265 codec of the S1 and the MP4 h.264 of the S1R. I have to say I was pleasantly surprised by the ISO performance but the codecs are just not as robust as I would like to see. What are your thoughts?

GetNavi posted those detailed Sigma FP images:

Engadget writes:

Is the S1R worth $3,700? If you had asked me this even a month or two ago, I would have said yes. However, Sony’s incredible new 61-megapixel A7R IV has put me in a tight spot here, based on the brief look we had. For $200 less, you get a lot more, including much higher resolution, phase-detect autofocus with incredible AI powered eye detection, and video features on par with the S1R.

Sony simply hasn’t given Panasonic an inch in performance, and has a proven track record with three previous A7R models. It’s a shame, because the S1R is a pretty incredible camera, but like Canon and Nikon, Panasonic is simply getting lapped by Sony in the mirrorless race.

Tyler Rostedt:

Over the month I’ve shot weddings, low light concerts, and have tested the Panasonic S1 a lot! Here are my thoughts testing the continuous autofocus, the color science, the 4k60 and the photo and video capabilities. And even compared it to my GH4