A simplify design makes the submersible head have a closer contact with the bottom of the pot or food container, where normally meals are pureed, the common round edges are only better when using a mixing bowl which isn't the most common, only when dressings like mayonnaise or pesto are been elaborated. The power has very convenient settings with a very variable speeds, not just low and high power. The only "but" here is there is NOT a low speed which might be convenient in some cases like delicate mixes and chocolate sauce.
The interchangeable accessories allows to prepare more than one mixture without need to wash your blender after every use, so your salsa, dressing and dip are made almost at the same time