Might as well recount my own Orbi experience, or rather that of my parents for whom I bought an Orbi for Christmas. They've got pretty much the worst possible environment for wifi — a very old house with stone interior walls and ancient electricals. For years they've been struggling with some various combinations of routers, powerline and extenders and still haven't been able to cover the whole house, hence the hope that an Orbi would provide a more robust and simple solution. Initial setup was refreshingly simple, after some brief confusion over ISP login details (you can bring a horse to Lastpass, but you can't make them use it) and where there was coverage, speeds were as good as with the wired powerline setup, if not a little better. Unfortunately the default (and easiest, given the layout of the house) setup with the router at one end of the house and the satellite in the middle left a blind spot at the other end.
A bit of research revealed that, unfortunately, Orbi does not actually use mesh networking right now, so realistically adding another satellite wouldn't help much. But, it turns out running a powerline from the modem to the middle of the house and attaching the hub there didn't degrade performance particularly and allowed the satellite to cover the far end easily. After a fair bit of effort, even this ancient, heavy-built house could be covered with one, non-extended wifi network. Yay!
I was slightly disappointed the satellite lights weren't battery-powered so you can't just carry the thing about to see the signal range. You have to do the whole power-on-sync process at each location.