ACE and ACA are two totally different things, while ACA evaluates your knowledge of use of the program for certain activities, ACE evaluates your knowledge of the tool, it is much deeper.
I recommend that you prepare using the guide exam (you will find in ACE) and use the "classroom in a book" and the program's user guide on which you want to certify.
Certification difficulty: ACE
For those of you who have completed the ACE, how difficult is it in comparison to the ACA?
Thanks!