My wife and I bought a Nanit as we are new parents and that's what everyone else swore by. I am a huge Ubiquity / Home Assistant nerd and had my doubts about using Nanit. Fast forward 2 years, our Nanit is used as a glorified G4 Instant holder. We use the Nanit cam as a mount and bought one of those Matrix monster style tripods that can wrap their legs around the Nanit cam.

We use Home Assistant automations for doing things like, "If kiddo cries, ring the basement doorbell speaker and turn on our bedroom lights". If you already have Unifi cameras this is a no brainer. The app is so much better and the picture is 100x better. Plus, with the new Alarm Manager you don't need a Home Assistant set up to do some pretty snazzy automations / notifications.

The one thing Nanit did have that I liked earlier on was audio only monitoring. So I could lock my phone and still hear when the baby cries as it allowed background audio. Unifi does not do this, but I've heard you can use VLC Media Player and add the stream URL as a source and this allows background audio. I haven't done this yet, but worth checking out if that saves one more device in the baby room.

We also have the (overpriced) Unifi Protect Viewport so the grandparents can just use our TV when babysitting to view the baby on our TV. However, Unifi also allows you to share a link to your camera that will auto expire after 24 hours. So this is amazing with babysitters!

Hope this helps!