It's good to hear you like the R9. I like it a lot too. On the other hand, on you description I can see, how everything is relative. To say that ball shoots out like a rocket with small movement. That it strange. For me the R9 has the typical chinese dense sponge, which, in order to get speed (for normal hits) a bit closer to ESN rubber, needs to be boosted. I love the feeling from these rubbers. But noone yet told me this rubber is fast like a rocket. In fact opponents sometimes even complain, that sometimes it is so slow it breaks their rhytm. Clubmates or players I train with mostly tell me I should get something "normal", where normal is something like D05, or at least RZ EH. They all without exception think this rubber (these kind of rubbers) is slower than the ESN/Butterfly rubbers. Perhaps if you boost hell of it, but even then (I couldn't even glue it), it was still less bouncy on "normal" hits, like on normal FH 1-to-1 drive play.
I notice things like that happen very often. Somebody say Hammond Z2 feels softish, team-mate has it on the FH side. We both feel it is simply too hard for the BH for us. I guess I want to say, what we feel about rubbers is so personal. To take something usable I need to read/see how someone here compares rubbers. Then I can get some usable info from it.
I play with these rubbers because I like it. I also think rubber like that, say H3 37-39, or B2 37, 39, etc. are good for returning or developing players. It forces you to do the movement fully, and it doesn't force you artificially slow down (brake) your movement, which is contra-productive. In that sense it can save time. Training is more important than rubbers, but having correct rubbers can save time, too fast can slow the progress down. I'm aware everything what I say is not new, but occasionaly repeating is OK.