Can I assume that there will be no more upgrades for Sonar X3?
Of the new versions of Sonar, which would be the closest to X3 Studio edition?
 
John
 

Sonar X3e was last updated in 2014 and is not a currently supported Cakewalk Product.  I still have it installed alongside of Platinum.  It runs on Windows 10 just fine, but Sonar has added so much since then, it's hard to compare.  Try the demo yourself and see!
 
You can compare the features of the current product lineup here to decide which is right for you.  My guess would be Sonar Artist is the closest to X3 Studio.  Then there is Professional. And at the top, Platinum, which replaced Producer.
 
http://www.cakewalk.com/Products/SONAR/Versions
 

jjdubs
Can I assume that there will be no more upgrades for Sonar X3?
Of the new versions of Sonar, which would be the closest to X3 Studio edition?
 
John
 

Sonar Professional is on the similar feature set package.  
 
You missed the upgrade path pricing which ended yesterday.  Now you will need to pay for a full version to "upgrade"

One thing for sure about using Sonar,, You really need to receive the Emails and pay attention if you have any desire to carry on. I think those E mails ( and reading this forum) has saved me 1/2 price on where I am at today which is a lifetime update of the full version.   I took some of those savings and bought Home Studio just for fun. 

I am considered upgrading to Professional  from Studio X3 but I do not know if there is any support beyond the database knowledge center.

Cakewalk offers email support for any current version of software in your Cakewalk account.  There is a link for email support next to every supported product listed in your account.
 
For older versions, the knowledge-base and online documentation is the place to look.
 
Then there is always this forum to ask questions and get advice from other users.