The adventure model in the US doesn't come with a top case either. Personally I would rather have the aluminum boxes, but I don't know that I could justify a 700 dollar difference between them.
However, the crash bars and variable windshield starts to bridge that gap. I didn't go with the US adventure because I wanted the Givi air flow windshield, and real bark busters (the suzuki models are just plastic, no metal spine) and the bags weren't worth 1500 bucks to me.
2006 Yamaha Warrior
2006 Honda CBR F4I