There has been a good deal of discussion of this subject on other threads, but nobody has been able to come up with a definitive answer. Most people simply assume that AW 1 bands are fully compatible with AW 2. I phoned Apple this morning and was unable to get a clear answer from them either. The expert said that he "assumed" this was so, but he wasn't certain, and consulting other people didn't lead to a more definite answer.