Thanks for your response Vladimir!
I've also found a thread from Esteban here and he does not recommend using script tasks.
I understand that under some scenarios a script task might be an option, however I'm integrating jBPM within JEE 6 and my beans are CDI beans so I need to get references to them through the container. As per what I have read so far, it appears that Task or Service Task might be my alternatives since I can inject and bind the work item handlers into the session however I'd like to know the difference between both (Task vs ServiceTask).
Thanks again for sharing your experience!