Ofir, this is true, I used to use the hard flex tube on the Hammond Melodions but the attack was not as sharp nor was the control. One thing that the tube does offer is more air, if you are performing a piece that requires a long phrase with many notes the tube is fantastic for this as it adds additional air to the chamber. If you have tried to do circular breathing you will notice that it is much easier with a tube than with a trumpet mouth piece, still possible but much easier with a tube. Some players prefer to blow right into the mouth piece hole. I like the trumpet mouth piece myself.