Upgrade to CMS
 

I did search for this but did not find an answer (or was too impatient to get the search right...?).

I am currently running vbulletin 3.X. I am considering upgrading it to 4.0.x since I can do that while I have a valid license. The question is this... The people who use the site are considering the CMS. Will I be able to go to the 4.0 forum software and then upgrade to CMS afterwards?