Why not to use Magic Quotes
    
     - 
      
       Portability
      
      
       Assuming it to be on, or off, affects portability. Use
       get_magic_quotes_gpc() to check for this, and code
       accordingly.
      
     
- 
      
       Performance
      
      
       Because not every piece of escaped data is inserted into a 
       database, there is a performance loss for escaping all this data. 
       Simply calling on the escaping functions (like 
       addslashes()) at runtime is more efficient.
      
      
       Although php.ini-dist enables these directives  
       by default, php.ini-recommended disables it.
       This recommendation is mainly due to performance reasons.
      
     
- 
      
       Inconvenience
      
      
       Because not all data needs escaping, it's often annoying to see escaped
       data where it shouldn't be. For example, emailing from a form, and
       seeing a bunch of \' within the email. To fix, this may require 
       excessive use of stripslashes().