Really pleased with my 3 x FlexHD (plus an old AC-Pro for guests & IoT).
Yes, there are some quite steep parts on the Unifi learning curve, but the UI community forum is extremely helpful and regularly visited by UI tech folk
Unifi is not plug & play, but when you get it going it just works (my AC-Pro has not needed any intervention or reboot for 4+ years apart from firmware upgrades).
Be aware that UI tries to suck usage data (blocked at my firewall).
If you are a home user, you should probably avoid the free cloud management UI provides unless you can imagine some use-case for remotely managing your home WiFi.…more