Acuda S3 has been the best soft rubber I've ever used. These soft rubbers are what I've tried so far: Desto F3 Bigslam, Acuda S3, Rakza 7 Soft, Aurus Sound, Omega IV Elite. I like Acuda S3 the best among the mentioned soft rubbers. It has a very loud clicking sound but less than F3 bigslam...