Great post Rowell, I've been using a WLAN Pi Go now for a while during some of the beta tests. Totally agree with you. This IS in a permanent place in my backpack.
Small, light, and yet very powerful indeed. My 'go to' tool has always been Adrian Granados WiFi Explorer Pro 3 on macOS... but now I get 80% of the same functionality and details on Wi-Fi from my iOS device connected with a WLAN Pi Go.
The larger WLAN Pi M4+ and R4's have their places as well... but for a quick testing this iPhone/WLAN Pi Go is a great solution!