If you're looking for top radio performance, not necessarily the fastest speed, get the Pro models, older gen / second hand if needed, especially if you have suboptimal physical conditions. E.g. concrete walls, metal, etc. I had AC Lite, AC LR and AC Pro in use at some point. All of them were very good but the Pro had the best overall radio performance. If you're in a wooden house with drywall partitions, probably all would do well enough.

Not OP, but I have one NanoHD upstairs, one IW-HD and one U6-IW. Basically bought them in that order when needed. The IW have the advantage to also act as Ethernet switch to a few devices like Apple TV and so on.

The U6LR is amazing but overkill. I use one to cover the house and hdnano to mesh with a uap-ac in an external building.

I use a MoCo bridge and two U6LRs to cover 1km of farmland.

Not OP, I've installed a little bit of all of them for work, every form factor and version seem to be stellar.

I installed a bunch of Enterprise 7s at work and they're super fast, but approaching chonky in size. Honestly, I really like the in-wall HDs They cover most of my house

The dream router is an excellent base to build upon. It provides all the normal functions (ethernet, wifi, router etc) as well as hosting the control software.

Unifi's real power is when you expand it. The access points make extending WiFi coverage easy. You dont even need a wired link. It will link over WiFi, either as a primary or as a fall back. The flex mini is also quite handy. It's a little poe powered switch. I have a couple tucked away providing extra ports around the house.

With my setup, I have detailed monitoring and control down to the port or wifi device. I can monitor and control things in detail, or get a high level view of my network.

My access points are AC Lite and and U6 Lite. Those are discontinued though.

If I get more for inside, I would probably get the U6+. I am also thinking about getting one of the AC Mesh access points for outside. I'm not too worried about speed since anything that needs high speed is wired. I don't have any neighbors, so I have all the bands to myself. If you are in an urban area, you should probably consider one with 6GHz support.