I have 3 grand stream Access points, two GWN7610 and one GWN7600LR. The indoor ones are strategically positioned in the house, roof mounted and POE and the LR is on top of the roof, my property is 3 acres. I have 40 something wifi devices connected to the network, mainly light switches and pool pumps, lights, tv’s etc. I do not have an issue, I can be 200 meters outside away from the LR and I still get good signal. They do not need rebooting etc. and so far I’m mega happy with the setup
I also have the Grandstream Router, I think the ubiquity stuff is better in that department but the grand stream can be powered by POE which is why I got it. The problem with the Grandstream router is that you can’t use it as a AP controller as advertised as it don’t support the TLS version supported by the AP’s …
I have two networks, one private one for guests and I don’t route traffic between them, the guest network can have client segregation so clients can’t see each other as well but this will not allow a guest to stream to a wifi speaker or airplay device so turn it on at your peril
The AP’s support multiple VLANs and multiple SSIDS per VLAN so you won’t have issues there, I would not hesitate to recommend Grandstream access points to anyone, even Cisco fanatics.