The main difference between a smoothie maker and a blender is that each appliance was designed to do a certain job.
A blender will usually have multiple functions, It has a variable speed and also a pulse function as opposed to the smoothie and sport 2 go they both have just the 2 speeds plus pulse.
A blender stands a lot taller than a smoothie maker and the base is always bigger because it holds a much bigger motor. Smoothie makers are usually quite compact and small and the cups are usually around 1-2 servings.
Our Blend-x Pro has an impressive 1.6L jug compared to our smoothie makers which are around 500ml-600ml.