Some right and wrong comments in the above.

AC controllers do certainly run hotter than DC due to the amount of FETS that are being switched and the frequency that they are switched, both of which are substantially higher than DC units.

Power consumption is less than that of DC........The reason for the stated 3% is that AC machines are generally more powerful in terms of speed and torque compared to a DC units, so if an AC unit was de-rated the power saving would be higher.

AC power is superior to DC because the motors are more controllable, powerful and cheaper in the long run due to the reduction in parts, especially for the motors.....just think no looking at another raised comm bar from an operator bulldozing a load!

In Europe we are manufacturing 36V (For the US market), 48V, 72V (Not so much these days) and 80V units, and the technology has been used in Lift Trucks for 3 - 4 years here already.