title: Are the advantages of Model-View-ViewModel (MVVM) pattern worth the overhead?
body: <p>The question is stated in the subject: are the advantages of Model-View-ViewModel (MVVM) pattern worth the overhead? </p>
  
  <p>In many cases, implementing the view model involves quite significant overhead of duplicating the Model properties and sometimes synchronization between Model and ViewModel data members. For example, currently in Silverlight 4 &amp; WCF RIA, View Models are not generated (if the developer follows the MVVM pattern, it is up to him to create the view models, often duplicating the corresponding Model's properties at ViewModel, that do nothing significant but refer to Model as the storage).</p>
  
  <p>Why not extending the Model class, providing additional properties to make it easy to be consumed by the View instead? </p>