I was only able to find one review of it, and it was a random YouTuber, and it showed Frost X25 idCooling thermal paste beating the phase change by 2 celsius, but I don't know how much I trust the testing process of that video. Also, Frost X25 is nowhere to be found for some reason.
I'm probably just going to play it safe with my tube of mx6, it hasn't failed me yet, so eh. For $4 though, its nice to have a little novelty item like this, and I might do a test comparison myself if I ever get motivated this summer.