I'm using 40A-L Orings on a cherry mx red keyboard (Corsair K70), and 40A-R on a cherry mx black keyboard (CM Storm QFR).
I bought both orings from wasd (blue and red ones):
http://www.wasdkeyboards.com/index.php/products/keyboard-accessories-2/cherry-mx-rubber-switch-dampeners.htmlBlue (40A-R) orings really improved gaming experience on my cherry mx black QFR.
Black switches have higher actuation force, so are slower than red switches, but a bit more precise (less typos).
Blue orings reduced black switches travel distances, making them "faster" (less travel distance to bottom out, faster moving to a new key).
I still consider reds superior for gaming, but I must say that blacks with blue orings are great.
Red (40A-L) switches didn't change too much the experience on my mx red keyboard instead.
Reaction hasn't improved that much, travel distance is more or less the same, I just gained a bit of silence which anyway isn't bad.
I left red orings on my Corsair K70, but I could live without them.
More time pass, and more I feel that one of the biggest advantages of Mechanical keyboards, in addiction to their inner mechanical quality, is customization.
So there is not a "better" or "worse" solution, most alternatives are subjective.
Experimenting leads to the best keyboard experience.
OFFTOPIC: I bought Corsair K70 after QFR, because I wanted to try cherry mx red. Now I understand when people claims that QFR (and probably Filcos, Ducky etc.) have better quality. Still, for a gamer, cherry mx red are generally so superior that personally I can move on worst stabilizers and not so good keycaps.
Add to this a wrist rest with great ergonomics (at least for me) and very nice touch feeling, and actually Corsair K70 is driving really great gaming performance for my needs.