Even though this is an older thread it’s still pretty prominent so I’ll add this:
I’m a fan of the Ubiquity cameras and DVRs - I have four systems at different locations but you should be aware that Unifi NVR is end of life. It will get bug fixes but no new major features. And the timeline feature on it is broken and won’t be fixed. It couldn’t be fixed with the architecture they used in Unifi video so they rewrote the NVR and the new version is Unifi Protect. And the timeline scrolls like butter, even over mobile cellular connections. Better than my Nest doorbell camera from Nest’s cloud even.
Unifi Protect is not yet feature complete with Unifi Video, but new features are being added at a steady pace so that doesn’t concern me so much. The potential sticking point for some people, especially those used to building their own NVRs is for now Protect doesn’t support that - it only runs on Unifi NVR hardware (Cloud Key Plus at the moment with rumors of more and bigger boxes coming) and they are not likely to ever support DIY NVRs with Protect in the future.
At first I was a little miffed over this, but after seeing how well the Cloud Key Plus works and for $200 if they can maintain that value proposition with larger appliances then frankly building your own NVR wouldn’t be worth the hassle. It remains to be seen, but I’m hopeful - three of my sites fit with the CK+ and one site I have a custom built NVR that I would love to move to a larger Protect NVR, if UBNT preserves the price/performance they established with the CK+. The UAS was way too expensive with much too limited storage for an NVR, for example.
So if you need 20 cameras or less, even if you start with Unifi Video you can always migrate to Protect later. If I needed 30 cameras today I’d be wary of investing in Unifi Video cameras today - there is some potential risk since the additional Protect NVRs are as of yet unannounced, let alone shipping. UBNT has changed direction on products in the past (like the USG XG). I don’t think that’s going to happen here - they seem extremely committed to making the video camera thing work (this is the third rewrite of the NVR in 7 years - if they weren’t serious they wouldn’t have bothered with Protect) but unless it’s shipping there’s no guarantee.
With any vendor if you need it and it isn’t shipping, it’s safest to act as if the vendor never will ship it and then act accordingly. It’s really hard to get bitten by broken promises if you follow that approach