In Use (continued):
The next step I took was to load up the WiFi Analyzer mobile app to see a few things. I was hoping to glean some info about the performance of the router and extender, and I was also hoping that the app could be used to help me place the two devices in their best locations, since the ALLY approach could be a bit more scientific to me. The extender has an LED on the front that will light up in either red, yellow, or green to indicate that it has been placed in an adequate location relative to the router. This works just fine, but I like numbers. As you can see in the screenshots below... My existing Wi-Fi network (Treetop) is shown as having two physical access points in the house, and the 2.4GHz and 5GHz bands are on separate SSIDs. We see that the signal strength for the Treetop network is better than than the ALLY network, but it probably should be... each device has three large external antennas, which probably give it the advantage over the ALLY system with its internal antennas.
In these screenshots, the ALLY devices were placed near the existing Treetop network devices. What the app shows me is that the ALLY devices would be better off spread farther apart, as the interference on the 5GHZ band was pretty high, which is notable since they are using the same channels. So, instead of having both units on opposite ends of my first floor in hopes of covering the basement, first floor, and second floors evenly, I moved the ALLY extender to the second floor. The interference dropped, the signal strength was similar, and the coverage did get better on the second floor.
Speaking of signal strength, the test results detailed below involved accessing the ALLY Plus Wi-Fi network from my laptop from various locations the house. Previously, this type of test had resulted in a wide range of performance results, and would quite often lead to dropped coverage as one access point handed off to another access point. I ran the Speedtest.net test from a variety of locations in my approximately 3000 square foot house, which has a basement (with garage built in), a first floor (where I located the ALLY router towards the garage side of the house), and a second floor (where I located the ALLY extender on the side of the house opposite the garage).
What we see is very uniform coverage within the house, plus the ability to remain on Wi-Fi in the backyard all the way out toward the pool. I am very pleased with the results, and convinced that this is the way to go for covering a house with goof Wi-Fi signal.