Ken, having just gone through this painful exercise, I'll ask you to consider the case where only 10 or 20% of the conceptual schema changes after reverse engineering in ways that will affect the mapping to DDL. In particular, this is a data warehouse, and most of the dimension tables had no need to change at all.
In many cases, the only changes were trivial, but needed to be seen to be trivial as well. For instance, I made several "name" objects mandatory, and a few were made one-to-one unique. In this case, a schema compare should have shown only a change from NULL to NOT NULL, and should have shown the addition of the UNIQUE constraint.
Seeing a change in column order was distracting, to say the least.