Show location of all wifi devices seen with 3 orpi routers.

There is no Map.  You just need to play around with it and test speeds.  Here is my expereince:

I origionally wanted a MESH solution to cover my 5,500 sqft house and a large court yard and patio.
 
I purchased the Costco Orbi solution which includes 2 satalites and router.  After about an hour of finding the best locations for the satalites we get the full throughput from our cable modem 300mbs in every room in the house.
 
We have six kids and always have people at the house.  Its common to have about 35 devices on the network.  We have just about everything including Apple, Samsung, PS4, Xbox, Chromcasts, AppleTV, Windows, Mac, Nest, Google Home, Printers,  and variety of TV's etc..  
 
I have yet to find a device that doesn't play well with the Orbi.  We rarely see sluggishness and in the month that we have owned the Orbi, we have not had to reboot it which is very uncommon when compared aginst the number of other Wifi systems we have owned.
 
I was origionally looking for a true MESH solution like Google Wifi but the Orbi's seperate Wifi attennas intrigued me.  Each Orbi gets great distance which makes the MESH not necessary although I wish Netgear didn't market this as a MESH solution.  
 
Its an expensive solution but if your Wifi is important to you... I would totally recommend.  Hope this helps,
 
Tim