Logitech makes good products but I've always felt that is where it ended. Make something good and barely support it. Its clear their focus is else where.
Seemed inevitable. Nobody is stocking them anymore. Hope that does mean a Circle 3 is on the way. I think these cameras are superb and one of the first players in HomeKit which I can respect. That 180 deg view is excellent and it be hard to switch to something narrower. Can cover more ground with fewer cameras. Perhaps a 4K version to compete.
180 degree view is nice however it zooms the image out too far (for me). Unless the camera is really good its hard to see small details like positively identifying someone by their face. 120-130 degree is the sweet spot for me personally that way I can mount it fairly far out of reach without it looking like its a video from a hot air balloon.
I bought an el cheapo Wyze Pan Cam just to play with and it has a 120 degree view but it can rotate 360 degrees. For 35 bucks I'm literally blown away (storage can be local). I would highly recommend Wyze cam and Wyze Pan cam if nothing but to play with or put somewhere you dont care if its stolen.
4k is tough due to bandwidth limitation. I have comcast with 150mbs down but a measly 5-15mb upload speed. A single 4k video feed with fast compression (h264) can exceed my bandwidth that making my internet useless. Using 2-3 wouldn't be possible. Using HEVC with a really powerful encoder in the device would be a requirement. 1080p is barely being leveraged, use an iPhone to make a 1080p video right next to your 1080p cameras for comparison and the iPhone will blow it away quality wise. The level of compression the IP camera companies use it WAY too lossy, some worse then others.