Speed drop at beacons
I have Spectrum, 400 mbs service to house. At the Eero router I get 400, but at the beacons I'm getting half that (around 200). I have rebooted everything with no change.
That being said, twice since I installed the system in December I've gotten the full 400 at the beacons, but it appears temporary. I purchased the mesh because the hard line is at one end of the house and where I need the most speed is at the other end. House is 3000 sq ft, first beacon is on same floor as router, about 50' away and the second beacon is almost directly above the first on the second floor.
I need to get 400 at the beacons or the system gets returned and I will have to find another system that will give me the speeds I need.
Probably no wireless mesh system without dedicated backhaul will be able to do that for you. The system has to share the two bands that the Beacon has with the backhaul connection between it and main Eero, as well as your client devices. Systems like Orbi will be able to do what you want in terms of speed, but my experience with both Netgear Orbi and Zyxel Multi X (both have dedicated backhaul bands) was terrible - really unstable and I had issues with satellites and/or clients dropping regularly, sometimes every day. You could hardwire a couple of the new Eeros to your system and will get full speeds everywhere if you do that.
I'd try moving the beacons around. Just because one is right on top of the other, one floor up doesn't mean there will be good connectivity. Maybe there is a bunch of electrical wire between floors or pipes or who knows what. I got lucky in my setup. I use ethernet to connect two of my Eero Pros and the third is one floor above one of those and it is working well.