title: To use Enterprise Library or not?
body: <p>I'm working with a multitier SOA based enterprise application with every complex business logics. Many business validations require large amount of support data from database, which slow down the performance. The number of concurrent users are about 1000. 
  The client is multitier with WinForms on top.</p>
  
  <p>We are considering almost all the enterprise library blocks.</p>
  
  <ul>
  <li>Caching Application Block</li>
  <li>Data Access Application Block</li>
  <li>Exception Handling Application Block</li>
  <li>Logging Application Block</li>
  <li>Policy Injection Application Block</li>
  <li>Security Application Block</li>
  <li>Unity Application Block</li>
  <li><p>Validation Application Block</p>
  
  <ol>
  <li>Is enterprise library right way to go?</li>
  <li>Please suggest libraries/frameworks that are better in your opinion, but consider telling way they are better.</li>
  <li>Would it be bad practice to mix enterprise library with other libraries? For example we consider using log4net for logging.</li>
  </ol></li>
  </ul>