The Mosquite Blender Expressio was a direct result of customer feedback. People wanted to be able blend in effects gradually or just be able to have different amounts of saturation throughout a live performance. An expression pedal input was the best solution.
With the original blender, there was only a knob available to control the amount of saturation. With the Expressio you can connect an expression pedal to be able to gradually blend or hands free control your amount of saturation.
Not only that, the Expressio has a built in BJF buffer. So if you were thinking about getting a high quality buffer, you can take out two birds with one stone by purchasing the One Control Mosquite Blender Expressio.