Always friendly and successful for a technical lego model that goes without difficulty. The engines are powerful enough to make it work properly, the steering is rather brutal (turns suddenly without progression and returns to the axis in the same way). The proportions of sizes and reproduction are successful. The fault I find surprising for a model of this award comes from the cracking sound of the gears of the cylinders !!!! Indeed, there 's no clutch on engines not to force on the gears when the cylinders arrive stubborn! it gives less desire to s' use, damage ....