The Alpha EVO 12 is the value-and-smoothness pick: $300 cheaper than the SC2 Sport with the smoothest signal in its class. The SC2 Sport counters with 17 Nm, class-leading build and True Drive software - more torque and a stronger build at a higher price.
So it is whether the extra torque and Simucube build justify $300. For most drivers the Alpha EVO 12 is enough base. The SC2 Sport is the pick if you want into Simucube specifically and value the extra torque and build.