So after some consideration, I may not go with the Scribbles. Our track is low-med grip dirt/clay. It's usually damp with no dust. Most people tend to run Positrons/Electrons in M4 compound. That is also what I run on my ET410 and my TLR 22. After asking a couple people, they are not sure if the Scribbles in MC compound will work. Any input? I read that MC compound is naturally harder but the type of rubber gives it traction, compared to 'squish' from M4. So is it worth trying the Scribble or just stick with an M4 Positron? Thanks.