title: NSURLConnection synchronous request from a thread vs asynchronous request
body: <p>What is the differance between adding a operation which make a synchronous NSURLConnection request in NSOperationQueue ( or synchronous request from a thread ( not main thread)) AND making a asynchronous request from the main thread ? </p>
  
  <p>Both will not block main thread so UI will remain responsive but is there any advantage of using one over other? I know in later method i can track request progress  etc but assume that progress and other HTTP stuff is not important here.  </p>