I might upgrade from X3 to Professional and notice that it requires the Command Center so am wondering if there are new restrictions on using Sonar with the current licensing?
How many PCs can I have it installed and activated on providing that I only use one at a time?
I might dual boot Windows 8.1 and 10 on my new laptop so that would be two potential installs plus I have a powerful tablet with Windows 10 I might like to try for the touch screen experimentation which would take it to 3.
Would this be allowed under the current licensing and how are activations/installs managed?

As many as is reasonable to do so.  
 
Technically now they have the ability to restrict installs if they see a serial number being abused, as before there was no check and balance that I'm aware of.  But the licences states you can install it on a reasonable number of computers.  I have it on 3 at the moment, myself.  

Thanks. 3 is the most I'd want to install on.
I do sometimes changes PCs frequently so is there a requirement to deactivate or uninstall prior to retiring a PC?

SmilingCrow
Thanks. 3 is the most I'd want to install on.
I do sometimes changes PCs frequently so is there a requirement to deactivate or uninstall prior to retiring a PC?

Nope, just don't retire the PC by donating it or giving it away with it loaded on there.  If it just sits in the junk pile, no problem.  

SONAR itself is not an issue. Bundled software is another matter. Celemony and XLN audio allow two active installations. Celemony also has an iLok option.

scookSONAR itself is not an issue. Bundled software is another matter. Celemony and XLN audio allow two active installations. Celemony also has an iLok option.

 
Two activate installs for Melodyne & Addictive Drums 2 is fine provided I can change one occasionally so is that possible?
 
 

SmilingCrow

scookSONAR itself is not an issue. Bundled software is another matter. Celemony and XLN audio allow two active installations. Celemony also has an iLok option.

 
Two activate installs for Melodyne & Addictive Drums 2 is fine provided I can change one occasionally so is that possible?
 
 

Yes, those you can activate and deactivate as you like via an internet connection.  
 
And AD2 is notorious for having to re-authorize it even when Win10 updates (which is very annoying, IMO)

I know it can be done with XLN having done it myself. I have no experience moving license around with Celemony.

Thanks all and sounds as if there are no licensing issues to stop me from upgrading to Professional.

Just curious.......
 
If you have it installed on say, 3 computers, and you're working offline, how does Sonar/Cakewalk "know" if more than one is being used at the same time?
 
~Jeff