I came across one of Oscar's articles earlier that compared the performance of a few GPS units. It inspired me to apply a similar methodology to the GPS units I have; an HGLRC M100 Mini, a Foxeer M10Q-120, and a Walksnail WS-M181. I tested them inside next to a window on a rainy day, so results are obviously worse than they'll be outside. All three units are new and have never been powered on since I got them somewhere between 6-12 months ago. I used Betaflight 4.5 on a SpeedyBee F405 FC with the same settings for all three tests. I didn't wire up the compass for the units that have it, and I don't know what effect not doing so has on the tests. Regardless, the results are attached.