VXL uses plain english to explain their ESC. Instead of Mosfets(metal oxide field effect transistor), they just say Transistor for short.

The lower the resistance the better and in this case the mamba wins. Topend motors are more efficient then the low end motors, which cost 4x+ more then chinese made stuff. High end motors produce more power with the same input. Then there is the other factor to consider, which is ...what is the motor built for? Torque, High rpm, massive HP, fast reving, or a balance of little of everything. The mamba is such a motor, with one flaw. It's not user rebuildable.

But yes, the brushless systems with the least resistance(more efficient) are also the ones that are more expensive. Is it worth to spend the money? If you are racing or just want the best, then yes it's worth it.