Ok this is probably a silly question.. BUT here goes..
 
I currently have Sonar 8.5, X2, INSTALLED on my DAW (I have all the other versions since S7).. and just bought X3. Haven't installed it yet.. but I wonder.. since the install files STILL show DimPro 1.5.. do i REALLY need to install it again? Is this one ANY different/better.. or is it the SAME DimPro that I already have from X2 PE.  Would I gain anything by installing this one?
 
And for the record, I think AD is a great addition to Sonar.. but is it intended to replace Session Drummer 3? Is Session Drummer still in Sonar X3? Just curious...
 
Thanks
 

Yes, Session Drummer is in X3

As for the second question, no, there's no need to either download or install the DimPro files if you already have v1.5

Session Drummer is actually pretty good. I would say with Addictive Drum you can tweak more and do more.