could you briefly compare Q4 with G-1?
Q4: the top sheet has more grip than G1 and the sponge feels harder, as a result any small and fast brush over the table are loaded with a heavy spin, however the arc is much lower than G1, as a result, in my case many 3rd or 4th loop while playing hit the bottom net. Due the grip and sponge, serves come with more spin, maybe more than G-1. In terms or returning serves both rubbers are excellent, good for touch, not spin sensitive and when attacking a serve is easy to overcome or kill the serve with a fast brush.
The 2 reasons (the only reasons) why I switched back to G1 were:
1. For some reason, I found Q4 difficult to control in regular warm up drives, ball was over the table or at the bottom of the net unless you apply always a brush motion with you wrist.
2. If you are attacking and find yourself out of position, with the Q4 the ball will probably hit the net.
My problems with Q4 were on the FH, most likely due my technique

, however with G1 everything just works, spin, smashes, etc, the arc of G1 is just perfect, it almost plays by itself

.
I also think I need more time to adapt to Q4, like many rubbers. However G1 is one of those rubbers you adapt at the very first stroke. I am not a fan of using two different rubbers on my blade but I'm thinking to combine Q4 at my backhand and G1 at my forehand.
Q4 produces heavier spins and the ball travels in a more linear direction, if are use to always brush, you will love this rubber, forget about Tenergy, Q4 is the real deal when talking spin.
G1 produces more arc, so it "explodes" when hits the other side of the table.
Other characteristics:
Q4 smells bad.
Q4 sponge is dark violet.
Q4 red color is matte, very nice looking rubber.
I would love to use Q4 again in the future, however at the moment is difficult for me to handle.