The Sette and Otto are the Picco with the lower carburetor. The case of the motor is different and the carb sits 5mm lower. The carburetor neck is also 5 mm shorter.

The internals of the Sette are the same as the EMX-WC and it's a seven ports. The internals of the Otto are the same but the Sleeve has 8 intake ports.
According with my personal testing, the eight port compared to the seven port makes more bottom end power. At the the same time, the lower carburetor configuration enables more bottom end power.

By no means the EMX-WC needs to be considered outdated. Picco has just expanded the line giving us different power bands options. We have to remember that in some countries and in the international events, 16% fuel is mandatory, so a little bit more torque in those conditions can make a difference.