```
1. return Request.CreateErrorResponse(HttpStatusCode.NotFound, "No product with ID = 1");

2. var resp = new HttpResponseMessage(HttpStatusCode.NotFound) { Content = new StringContent("No product with ID = 1") };
   throw new HttpResponseException(resp);

```

[This guideline](http://www.asp.net/web-api/overview/web-api-routing-and-actions/exception-handling) for exception handling in WebAPI describes both of above approaches. 

When should we `return Request.CreateErrorResponse` (#1) and when should we `throw an HttpResponseException` (#2)?