Kevin,
I agree, your tractor sounds like the peddle is out of adjustment. It should glide to a stop. Are you taking it back to the dealer for adjustment under warrantee?
Also, on the spec you list, that is the MAX distance. I don't think there is a MIN distance spec.
I looked in my service book (Grand L series only - sorry) and there is a neutral adjusting rod, so you can get it adjusted. (If it is the same as the grand L). My guess is that neutral is not centered on the peddle and when you let off, it goes a little bit into forward, causing the wheels to lock and a harsh skidding stop.
jb