Backup and Restore

What are the Negative Aspects backup and Recovery in sql server Over these points.

1. 
   

   Full Backup and Restoration

   
   


2. 
   

   Point in Time Restoration

   
   


3. 
   

   Restoration in Same Instance

   
   


4. 
   

   Restoration in Different Instances.

   
   

Please help me out regarding these points as to know what are the negative points... Please do reply As soon as possible..