I almost went with my qnap NVR solution too, but it was time to replace the cameras I had as well, since my outdoor cameras didn't have working microphones.
The biggest factor for me in the process was ease of setup / Wife Approval Factor. I setup our Blue Iris system just before we had our first kid, and now that we have two kids, I have almost no time to tinker / fix / upgrade my self hosted things, so the unifi protect was the solution that ticked most of the boxes.
The unifi stuff just works, but the included storage with the cloud key (their hardware NVR for small deployments) only comes with a 1tb drive. I have considered upgrading that drive, but for now I only have it set to record when cameras detect motion, and with 6 cameras I've yet to come to a point where I wanted to pull a recording from after it's been purged due to space. But there are times that I wish I had recording always turned on, I just haven't done that yet.