I went for 2.1mm rubbers for both backhand and forehand like the chinese style but some recommends thin sponge.
What do you guys prefer for beginners?
It depends. do you have a coach or not? If you have a coach, you can get whatever thickness you want.
if you don't have coach, I would recommend 2.0mm for most players. Too thin, you might not learn how to loop and engage the sponge properly when learning top spin loops. If players want to start with 1.8mm, I would be fine with it. If you want to learn all the proper techniques that are aggressive (like looping, smashing, etc.) then 2.0mm or up is what you plan to get environment.
Less than 1.8mm is often used by choppers who want to have good control on the chopping with forehand.
However, some modern choppers probably have 2.0mm or 2.1mm or max sponge on the forehand side because their goals now are to attack with forehand aggressively. The backhand long pips are merely there to set up the forehand.
