Grinder Electronic

Hi everyone, the latest in the purchase of a coffee grinder, unfortunately, do not stand me on Mythos One, so I am asking for advice on what to take note of when buying an electronic grinder:

What will be better in choosing for my espresso: ( Daily consumption of coffee 2Kg )

  1. mill with parameters:

Blades revs 13350 / min
Blades 83mm Steel or Titanium blades 83mm

  1. mill with parameters:

Blades revs 900 / min
Blades 75mm Titanium (Mythos blades)
or just Steel 75mm

Does anyone know how it works, maybe seen at the fair in Italy in Milan
The system in the Fiorenzato , XGi coffee grinder, the quantity of coffee dispensed, calculated in grams and set ONLY ONCE, will not change, guaranteeing precise waste and avoiding any waste. Is it working ??