I realize this reply is several months too late, but I just saw the post & figured I'd offer my thoughts. We moved from a nest camera to a Logitech Circle View camera using Home Kit.
We stuck with the nest cam for a long time because we were on an old plan that offered continuous coverage for the last 5 days vs HomeKit only offering video when something happens. But nest kept trying to move us to a newer plan that had the same 'only saves recordings when something happens' as HomeKit.
nest kept raisin the price of the storage. I think it got close to $100/year for the service. At that point, I figured it was worth exploring HomeKit, so we got the Logitech and ran them for several months next to each other. The Logitech/HomeKit works almost exactly the same as the nest one, which is good enough for our needs.
The Nest camera was definitely slightly better resolution at night, but they are both close & I'd imagine there are better HomeKit cameras out there now than the Logitech we have.
There is one weird glitch with HomeKit cameras that I've run into. If I scroll back & play some video from earlier today. Wherever I start, the first clip will play, but then the next clips just shows up as a totally black screen. If I let it go on, eventually the next video or the one after that works. I can then go back & review the clips that showed as black originally & they will now show up regularly.
I did work around the only works when it detects action by creating a video section to keep an eye on that includes the entire screen, which includes a portion of the street & gives me a lot more recording time than just focusing on the front yard of our house.
Overall, happy with HomeKit Secure Video, especially since it's basically free for us & were were paying almost $100/year for the nest version.