The Koga is the Lincoln Town car of touring bikes ready to go from the start. I've seen the World Travel up close and it's all quality from top to bottom. The Trek 520 doesn't even compare with this bike and it's not really fair because the Koga is more than twice the price.
The wheels and tires for the Koga have quality written all over them. I believe it also has a hub dynamo and an internal lock, Brooks saddle etc, etc. The Koga would probably be the only bike I would buy in Aluminum because it's so well made. No it's not light and was probably the most heavy touring bike I've ever picked up but also the most stout.