I've had the Dream Machine Pro for a few years. For work, I've built a small data center with Juniper equipment so I've had experience with a complex network. When choosing network equipment for my home, I wanted something robust, yet simpler and cost effective. After a bit of research, I settled on Ubiquiti. The ease of setup, management, easy to use web console and iOS app met my needs. The vast array of compatible access points, cameras and security products allows you to grow and stay in the ecosystem. I anticipated I wanted to purchase cameras in the future.
At this time, my Home Network has three access points. The access points were easy to install and pair. They handle around ~36 connected devices at any given time. Three separate VLANs are utilized for trusted devices, IOT and a guest network, all broadcasted on 2.4Ghz and 5Ghz. This allow traffic to be isolated and controlled separately. I wish the router had a handful of POE ports to support the access points. I'm having to use POE power injectors - not a big issue but a bit messier cable and power wise. A while after I purchased my router, Ubiquiti released the Dream Machine Pro Special Edition that has just that, 8 POE ports. If that was available when I purchased mine, I would have bought the special edition simply for that reason.
Updates are provided regularly for the router and access points. I've never had any particular issues with any of the hardware or software. The console UI can be a bit cumbersome, however compared with others, I can't complain. Ubiquiti is in a unique market of prosumer, sitting above Netgear and Linksys, and more friendly than Cisco and Juniper. I appreciate a company that is straddling in the middle for those that want a little more for home, or for a small business that doesn't have extravagant requirements.
After the initial setup, most of the time, I don't think about my network and that's exactly how I want it. Transparently working in the background and easily accessible if I need to make adjustments. It just works - at least for my needs. Your needs and experiences may vary.