I am only a keen amateur. Do professional players use hard solutions?
I do not think so. I have got a list with types and brands the top 20 players play with. It is true that they never use thicker rubbers than 2.0 or 2.1. But the hardness? I really don't know.
These very max sponges were found to fit the 40mm ball, to take the same effect on the nowdays balls as 38mm balls. I have tried Joola Terminator 2.6 and Donic Supersonic S40 2.3 and I found them harder than Bfly Sriver FX 2.1 or Yasaka Mark V GPS max or Joola Tango Metallic 2.1. In my oppinion if the pro players wanted to use something hard they would use Joola Cava or Moskito or Friendsip rubbers...
Everything is relative
