Quick question, Is it worth moving from Sonar X3 Essential to Sonar Artist? 
Thanks in advance.

It depends what your needs are. They look to be pretty evenly matched for instruments and effects, so I would recommend checking out the Versions and What's New pages to see if the feature differences (e.g., Ripple Editing, Lenses, PRV enhancements, etc.) are worth the money to you.
 
http://www.cakewalk.com/P...s/SONAR/Versions#start
 
http://www.cakewalk.com/Products/SONAR/Whats-New#start

Welcome to the forum. Quick answer; yes, Sonar has come a long way since X3 in my opinion. http://www.cakewalk.com/Products/SONAR/Versions
 
Rocky