Several videos show it falling behind above 20 mph and if the environment is complex like trees etc. it will slow as it deals with it and the speed can be even significantly lower. If it loses you it stops and hovers.
I just watched a video of DC Rainmaker running down a hill with Active Track, not very exciting. I guess I could use in on MTB downhills, where there aren't many trees. I was hoping to get sone action videos of me riding downhill on my road bike, but I see would very quickly outpace it. https://www.youtube.com/c/Dcrainmaker