Never really understood the fascination with two drops versus one. The drops really don’t add much of anything to the ride - they aren’t really big enough to be thrilling and having two doesn’t add anything to the “story” more than one does.
I just think two is more fun, but I suppose you don't *need* two from a storytelling perspective.
I do think the drops, more often than not, add to the story of the ride in that they signal a transition. For California and Tokyo, it's a clear shift in mood, tone, and setting (in California, I often find that people talk through the bayou bits, and the drop is an indication to
shut up and pay attention, and I find that to be a useful function to the drops other than the practical and fun purposes they also serve).
As mentioned above, Paris uses the drops to punctuate action in the story.
In Shanghai, the drop is similar to Paris in that it's an escape from an increasingly perilous situation. It's a release and a resolution.
Orlando is the one version of the ride where the drop feels most marginal and inessential. It certainly indicates a change in the ride, from the caves to the AA town scenes, but the drop is so slight that it almost makes you wonder why they included it in the first place.