Okay, so, first try was akward, maybe because of cpu consuming app behind (deezer ?) second try was much more convincing.
-almost 30% fps gain, but generally (as number don't really matter) really more "smoothness" in the middle of fight intense moments.
-no crash on the whole evening.
I can't say that it was the case for all my teamates, alas.
So, it doesn't hurt to say it from time to time, but Thank You, Valve.