I've put almost 2000 m. on my GTI. The more I drive it, the more I like it. It's great fun. VW should be applauded for building a terrific car for reasonable $. There is really no competition for the GTI, except for its cousin, the Audi A3. The GTI is quick and handles great; it even sounds wonderful - similar to a Honda VTEC at high rpm and it has a low growl when you give it some gas at low rpm. The rest of the time, it's quiet, as it should be. The build quality is excellent, too. The Civic Si, is no match for the VW in every day driving. The VW has much more low/mid range torque. It's a joy to drive and the Civic would be a chore. And, the GTI's hatchback design is much more practical.
Power; handling; interior quality and features, including Sirius radio and seat heaters; practicality; nice shifting 6 speed, looks.