I also have BlackVue. I only have it in front I have the newer 900? Model, 4K. Waste of extra money.
I like the form factor of the camera. And if you mount it as I did, right under rear view mirror, you can’t even see it when driving.
What sucks about it is you are limited to 1 minute loops in 4K, and only up to 3 mins in 1080p.
The app isn’t great but you get used to it. It’s relatively ez and quick to download clips, but tough to know which clip you want. But it will lock a clip if it feels a certain G force if you set that option.
I don’t know which camera is better however as they are all Chinese made and they write the apps so they are weak.
I was hoping Sony, Panasonic, Nikon or Canon would make one but hasn’t happened by now they will miss the boat.
I still recommend the BlackVue in spite of its shortcomings. And our Stanley Cup winner above is correct about the WiFi. ;-)