After several years of use, I can say that Ubiquiti software and support are trash. Their configuration app (I used the iOS version) almost never works, meaning that it almost always fails to find the AP that is one foot away from the phone. It also suffers from unprofessional UI-layout defects. Their Mac app won't run until you manually strip quarantine flags from it because it isn't even signed... then it won't run because it relies on Java 8, and Mac OS hasn't shipped with Java in a decade. And if you jump through enough hoops to get it to launch, it fails to detect any Ubiquiti devices.
Once I somehow tricked their iOS app into communicating with the AP and got it working, it did work for years and has pretty good range.
But now (and this appears to be a somewhat common problem), the AP randomly stops sending data on 2.4 gHz. Here's one of several posts about it: https://community.ui.com/questions/AP-AC-Pro-problems-with-2... And it appears to afflict multiple products.
This can last from minutes to days. Although you're connected to it, you can't even hit the router. Ubiquiti support is utterly useless; it's as if they do everything possible to drag out interactions until you go away, providing vague, terse, one-sentence answers every couple of days that contain no specifics.
My impression is that Ubiquiti is just hanging on, coasting on existing technology and doesn't even have support staff that knows how it works.