All Mesh systems are not created equal. There are single band, dual band and tri-band. The key is how they use the backhaul and over which bands it is used. The backhaul is how each Access Point (router/node/etc.) communicates with each other. The fastest and most reliable, of course is wired backhauls.
In a typical dual band system, without a wired backhaul, you will have typically 1 2.4GHz band and a 5 GHz. When the wireless nodes talk to each they will consume one of the bands which bottlenecks transfer speeds. Typically it would be the 5 GHz band unless the range is far between nodes. If it is using the 2.4GHz then you usually see a larger degradation in speed. So in essence the speed from your wireless device to the node would be strong, the internet connection to the primary router is strong but connection between access points becomes slow/bogged down. This is a typical problem with Mesh System that are not structured correctly or only have two bands. Of course it will also depend on how many devices you have on the mesh at anytime. This may not be an issue for just one or two, but bring that number up a lot + with smart devices, cell phones, streaming tv's, computers, security etc. It always creates a bottleneck.
Tri-band Systems will have one 2.4GHz and two 5Ghz so the wireless backhaul would consume one of the 5Ghz bands and make it dedicated. This greatly improves performance and are the fastest Mesh systems available today.
A system like I am running at home is a Tri-Band Mesh System. But I use a wired backhaul, Cat 6 between 3 Mesh Routers. The main router in my home office. One Upstairs and one out in the garage. Additionally I have 3 others which are using wireless backhauls out near the pool and then one back at the rear of the property for range, also one in the basement. Of course wired backhauls are superior in performance on a Mesh system than wireless for speed and continuity. Unfortunately running Cat 6 between some points may not be an optimal solution for some. As I remodeled the house I ran the cabling this last year. I wired backhaul gives you significantly more bandwidth and speed, but a Tri Band Mesh System is the next best thing with a dedicated backhaul.
The other key is also what type of wireless you have. Wifi-6 (802.11ax) is up and coming with full backward compatibility is important. AX if you are buying new which will support a/b/g/n/ac. The other important part is data rate and processer speed of the routers. 1024-QAM high data rate 20/40/80/160 MHz bandwidth
I currently use the ASUS AiMesh system. Which is fantastic because you can continue to grow the system, add more nodes with any of their ASUS routers that support Mesh. So for instance my main router which also controls firewall and security is a
ROG Rapture GT-AX11000 | Gaming Routers｜ROG - Republic of Gamers｜ROG USA (asus.com) and then I use different ASUS routers as access points. You can even use older models as long as they can run the AiMesh firmware, software update. The granularity and configurability of the ASUS Mesh System and routers is the most robust I have seen.
Another fantastic feature of the ASUS AiMesh system is I can easily assign each and every device a preferred node and preferred band and/or channel. So I have my lights and camera's riding on specific bands and connecting to specific nodes. My appliances on different channels, streaming and computers delegated as well with QoS, so that when the entire family is streaming something on every TV and gaming and all their friends are over and using my guest wireless, my computers take priority on channel and bandwidth. Pretty cool stuff. Not too mention I can schedule any band, channel or node to allow connections on a schedule. So for instance I shut of guest wireless at certain times and change priority to cameras and security at night.
Tested through put on my system out the modem to the internet is Max at 1.03 Gbps (1036 Mbps) over the wireless. This is based on my laptop or other devices that have wireless AX cards in them at peak load.
For many users this type of speed and resiliency is not needed. I am in IT and connectivity, latency, saturation, speed and security are big priorities for me from my home office.
One more point of note is that not all Mesh system can use wired back hauls, if you consider doing that someday. If it is a consideration I recommend purchasing as system that has that capability in case you want to use it down the road.
I did replace my outdoor wall lamps with ones that use Wiz (owned by Phillips now, but different than Hue). The interface is clunky, but they have integrated LEDs that you can pick the color, and it comes with holiday color settings preprogrammed.
