Air Law as an introduction to the theoretical training is enough to put anyone off doing the groundschool. I start them on Aircraft General Knowledge which is far more relevant to the flying training up to first solo. They usually crack this off well before first solo and then also get air law done as well.
Most schools get the students to do Air Law first as an ars* covering exercise in case of problems. A good ground brief on the essentials is a good back up plan in case they don't get air law done, and a signed briefing sheet to say they received and understood the air law brief.
I personally would rather the student understands the forces in a turn and mechanics of flight thoroughly than the Chicago convention.
jsf