For one of my applications, I needed a long range WIFI connection. I planned on using the AR300M16-Ext, but it was not very good at picking up weak WIFI signals. For another application on my PC, I had already purchased the Panda PAU08, so I tried it on the AR300M16-Ext, and it was much better and had no problems reaching multiple distant WIFI APs, BUT the GL iNet software kept over-writing my manual LUCI configuration, so I gave up, and just went with the generic 19.07 OpenWrt software for this application. The Panda is not just an antenna but is a full WIFI radio, so you end up with two radios, one that is connecting to the remote AP, and one that is used to access the local systems, which runs faster as you are not sharing a single radio for receiving and re-transmitting.

I would not use a Mango if you ever want to use generic OpenWrt firmware, as it uses a proprietary WIFI driver supplied by GL iNet, but not available in the generic OpenWrt firmware.