Thanks everyone, lots of good info here! I talked to my vet again this morning, and she said she still felt ACE was the best choice for Fletcher. She had just come back from a vet conference where they discussed Valium, and how it is being reported, recently, as having unpredictable results in some cases. Still the best choice in many instances, obviously, but not fail safe by any means.
At any rate, I am going to give him a half-dose tomorrow and see how he reacts, and we will go from there. I will let you know how he does!
Storms don't seem to bother him much, BTW. We have tried Benadryl, Melatonin, DAP, Rescue Remedy, Canine Lullaby CD, t-shirt, TV & AC white noise, some other herbal thing that I forget the name of ... anyway, I hope this works!