I always create a unique one for Ezine and a unique one for my blog. That is just the way it works for me. As those two are the most important I want them to rank high and have a high click rate, too. if you are after the backlinks only, on other directories, that is OK to submit the same. 
Actually the software I use for mass submission just takes the raw coded spun content and submits different spun articles to various sites. So you only put int he content once.
	
		
			
		
		
	
				
			Actually the software I use for mass submission just takes the raw coded spun content and submits different spun articles to various sites. So you only put int he content once.
							

 
