The promotional page for Producer X3 on the Cakewalk website includes the following item:

NEW! Get authentic drums sounds with the full version of XLN Audio Addictive DrumsWhat exactly do the words "full version" refer to?  When I try to use it, all I see is a subset of XLN's Fairfax Vol 1 kits.

Did you register it with XLN and use XLN's online installer to dl the full version?

Thanks for the quick replay.  I thought I had.  (I just got an X3 upgrade with included it.)  
I went back and re-entered the registration and got more:
Studio Rock
Studio Pop
Studio Prog
Fairfax Vol. 1 Demo
Pearl Masterworks Piccolo Snare
 
Does that look complete?
 

It depends on what you owned before. You get certain pieces of the Fairfax but you have to still buy it for the full pak.
 
If you did not own any AD stuff before, then that probably is what you get with AD2. You can buy other AD paks to add on what kits you like. It depends on what style you like.