I use an EdgeRouter PoE and two UniFi AC AP Lite.
I had to delve into the command line via telnet to set the ER up as I wanted. You can do a lot in the GUI web interface but not everything. (I run a zone-based firewall with a lot of inter internal network rules, and a number of different VLANs to keep trusted and untrusted devices separated. (I don't trust my (Chinese original) CCTV cameras, for example, so only allow them access to a time server on the internet and to the server that stores their video; nothing else; VOIP is separate, as are untrusted IoT devices (heating controller, solar panel monitor, ...)
The nice thing about the USG is that it is fully integrated with the UniFi controller so you can manage everything in a single GUI screen. But the USG GUI allows you to do less complex things than the ER GUI. However, If you've got straight-forward requirements, i'd go with the USG.
Beware though, if you need/want to run Deep Packet Inspection, or traffic policies, you are likely going to want beefier hardware (if you have fast broadband). An ER-4 comes to mind (and is on my upgrade list, together with a 3rd AP).
I have 150/30 internet, and even with a simple drop-tail traffic policy (which crept into my configuration during a firmware update) I wasn't achieving full line rate.
I've found the ER and UniFi units to be extremely reliable once configured, only being rebooted for periodic firmware updates.
Simon