Quality wise though XR15/XR30 are the greater choice. I mean kessil doesn’t really respond well with warranty while Ecotech who makes Radion does well. I know the difference between the 2 I had both. Currently using Radion xr15 G6 pro. The control app is decent. Just watch a YouTube video for 5 mins and your set.Both lights will work well but there's one thing that is for certain, I absolutely hate using mobius as a control method.
The while the kessil app itself isn't the best thing in the world, it's at least a lot more functional (for me) than mobius is and the insanely huge benefit of the ap9x is that it works even without the app (you miss out on controlling the violet + green + red however) or you can simply use iota to link it to your apex if you have one for easy control that way without using the kessil app
TLDR: Ap9x wins for me between the two.