The charger uses the atlas stage III base made with carbon injected.
The sl base material changed this current year to no carbon injected b/c of the charger to better diversified b/t the product lines. It is the same base model just no carbon.
2013 charger binding atlas base III = 2012 SL atlas base III ( both carbon injected)
2013 Atlas binding base III = 2013 SL atlas base III (no carbon injected)
I have the 2012 SL. I love the carbon injected baseplate, super stiff and responsive. I wonder if I could just buy Charger highbacks from c3. Had I known they were going to make the charger I wouldn't have bought the SL's.