Well, if you think about it, my starting dose was actually 12.5, so my drop is around 10% from the initial dose.
The pharmacist was kind enough to provide an all-purpose prescription to help control cost: at 1 mg/1ml, it's easy to speed up or slow down the reduction. If you want to cut by a modest amount, you take a little less fluid; if you want to be more aggressive, take much less fluid. It allows you to be as aggressive or conservative as you wish, without having to purchase a different prescription.
The current prescription supplies enough medication to see me through a 1 mg reduction every two weeks, until the drug is eliminated (10 weeks, estimated).
I'm feeling quite well today, and wonder if I've simply weathered the drug change storm. I note that Sylvia, who participates on my buddie blog, reports that her switch from Ambien CR 6.25 to Ambien 5mg also produced some turbulence after a few days. The two do not appear to have a convenient direct equivalence. That's good info for anyone else who may plan to taper from Ambien CR.