Well, I think with the PAT the more practice the better but the Royal flush edition seems like it might be overkill for most people unless you really need the extra practice. So, I guess what I am saying is that it comes down to how much help you feel you need with this section of the test. The Ace edition seems like enough practice to me so thats probably what I would choose, but if you choose the royal flush edition, its cheaper through Amazon.com then through the crack the dat site.
Crack the Dat PAT from Amazon