They use Suricata for the IDS/IPS. I have a UDMP, and I route 2.5GB a second across two load balanced connections (fiber and cable) on full IDS/IPS with no problems. I have logging going to greylog without any issues, but am looking to move to Loki. I have a UDMP, with a single 8TB disk for my camera, but you can grab a UNVR if you need more storage. If you need two, grab two UNVRs to cover a whole site. They pair now. And if you are a prosumer instead of a homelab / busoiness site grab a UDR, with a fast flash disk. You can pair that into Homekit secure with Homebridge (or even better, Scrypted).
I have 5 Unifi 6 devices - zero problems with them in well over a year at this point. I get 800mb/s from any location on-site.