I don't know a thing about guitar cases, other than my friends have them, but I can tell you about fiddle cases. Some fiddle cases have a hard exterior, and the inside is designed to suspend the fiddle, so that in the event of a fall, the fiddle is not apt to be jarred--the shock of the fall is not supposed to be transferred to the insturment.

I don't know if they make such a thing for guitars or not, but I would imagine that such a thing would provide optimal protection.

Greg