Matt,
At one time Morrison and O.L. were working together and putting the ACS limbs on Bob's bows. They are no longer doing that but I wouldn't be surprised if Bob did a little tweaking of his own limbs!
Chad,
By ACX do you mean the ACS CX? Or is the ACX a new version that has just come out?
The bow pictured is used and is about a year old and just the standard CX.
To answer your question, I've had 4 regular ACS bows and this will be my 3rd CX. I really can't tell any difference between the ACS and the CX as for as how the limbs feel...