I still don't see your confusion. 
 
Sonar series started way back in the last decade and they worked the way through the numbers 
Sonar, Sonar 1, Sonar 2 Sonar 3 up to Sonar 8. The new decade brought X1, X2 and now X3.
 
And Sonar is also released in 3 different levels and price points 
http://www.cakewalk.com/products/sonar/versions.aspx
 
Sonar    
Sonar  Studio 
Sonar  Producer. 
 
 

So, Sonar X3 is the top of the line product, right?
 
And:
X1 = Sonar 9
X2 = Sonar 10
X3 = Sonar 11
 
And the reason for the forum entitled "SONAR Producer and Studio" is for the old versions, the guys who don't upgrade, right?
 
 

BeachBum
And the reason for the forum entitled "SONAR Producer and Studio" is for the old versions, the guys who don't upgrade, right?

"SONAR Producer and Studio" was the main Sonar forum before X1 existed.  When X1 was first released they created a new forum for X1 (which subsequently became the X-series forum) and left the old one to be used for the older versions.  They really should have renamed it to avoid confusion.

spacealf
Version 8 is not Version X1 and I I think version 8 went up to version 8.5.3 with patches...

It's not that simple.  Sonar 8.5 was released as a whole new version, completely separate from version 8.  Insane really.

BeachBum
So, Sonar X3 is the top of the line product, right?
 
And:
X1 = Sonar 9
X2 = Sonar 10
X3 = Sonar 11
 
And the reason for the forum entitled "SONAR Producer and Studio" is for the old versions, the guys who don't upgrade, right?

Yes. X3 Producer is the top of the line, SONAR X3 Essentials is the third in line.
It can't be that difficult! Why do you make it so complicated?
Although X -series is so much different from <8.5 that it's no use referring to them as SONAR 9 etc.
If you see someone talking about version 9, he propably means Cakewalk Pro Audio from the 90's. 
SONAR 8  is never called Cakewalk Pro Audio 17, is it?
 
You simply use the forum that supports the software you want to ask about.

BeachBum

So, Sonar X3 is the top of the line product, right?
 

Well yes and no, X3 PRODUCER is the top of the line Sonar product. 
X3, is the bottom of the line, X3 Studio is in the middle. 
 
Sonar X3e Producer is the top of the line latest release.  

Ok, great. By golly, I think i got it!
 
Thank you!