Deco X50-Outdoor

I really like my Deco. It's not that model, but I do like mine. Start with a three pack, and then - yes - add the X50-Outdoor to it. That should be a good start. Then, see if you need a fourth inside. 5500 sq ft is pretty big so three may (or may not) be sufficient. You'll have to see based on location, building materials, etc...

The three pack sounds like a perfect match to me, unless you have an oddly laid out home (and probably even then). If you are able to run an ethernet backbone, that is always best, but mesh mode should still provide really good wifi coverage. All Deco units are fully compatible, up to the individual unit's capabilities. The X50 area won't benefit from all the BE95's capabilities, but it won't downgrade the BE95 performance in any way. So yes, you can add the X50-Outdoor to a BE95 setup.

Been really happy with my TP Link X50 POE. I'd try and get your APs out a bit more. Also, as mentioned, run Cat6 to every TV location, and where you think you might want cameras in the future. https://preview.redd.it/um692knyhlqf1.png?width=1080&format=png&auto=webp&s=fe596a268635480f80114a9aed9a49d497754f09

DECO X50 PoE Mesh with Backhauled Ethernet Gigabit WiFi everywhere $300 for a set of 3 Lucked up at MicroCenter and picked up 3x sets of 3-Packs for $100 each! Installed 5 at my business and used the rest for my new home build Nothing but reliable! Over two years of usage at my business and we have over 100 devices consistently connected

I think any of those 3 would work for you. I personally have setup my home network on the Deco X50 mesh system with 4 AP in total, and my smart home network in Home Assistant. No issues at all and provides a fair amount of control over your devices and network (priority, IP reservation, preferred bands/AP, etc. ).