Hi, @AdamH! I think that the difference in sponge thickness between 1.9 and 2.1 will be significant. At least I feel the difference between 2.0 and 2.2 mm for other rubbers, such as H3 and J3. For me, it's just night and day. 2.0 does not play the way I need it to. Less dwell time, speed and...