title: What's the recommended version of ECMAScript that my TypeScript should compile to?
body: <p>I'm working through Angular2 tutorials, and I've been going through each section until I opened the <code>tsconfig.json</code> and stopped at the following: <code>"target": "es5"</code>. This means that I compile to ECMAScript 5. </p>
  
  <pre><code>{    
     "compilerOptions": {    
       "target": "es5",
       "module": "commonjs",
       "moduleResolution": "node",
       "sourceMap": true,
       "emitDecoratorMetadata": true,
       "experimentalDecorators": true,
       "removeComments": false,
       "noImplicitAny": false
     } 
   }
  </code></pre>
  
  <p>I'm currently using ES5. Should I change the target to <code>"es6"</code> or <code>"es7"</code>? What's the advantage of using later versions?</p>