This is exactly how it is for me too. Everything truly "just worked" - except Sonos, but that's not a Unifi problem - they even have a dedicated page in their docs on how to set up Sonos systems, which I followed exactly, and it now works a treat.
I've also had three instances where upon rebooting due to a power outage or a system update, my inbound firewall / port forwarding was just broken. UniFi simply did not pass packets to my server. Once again, a full reboot of every UniFi device on the network resolved it.
I really want to like UniFi, and I appreciate how much access I have to SSH in and figure out what's going on (and I did take tcpdumps and have a support case open), but it has definitely not been plug-and-play for me.
I'm using a UDR7, U7 Lite, a number of managed UniFi switches, and just recently added the U6 extender.
The primary case I have open currently is in regards to the port forwarding / routing breaking on some restarts.