The i-racer has digitally proportional steering and throttle, and an infrared transmitter means that the range is extremely long- as long as the transmitter is in line of sight of the car. Two motors give the i-racer much more torque and speed than a standard bit char-g or zipzap. My personal favorite feature is the storage pod/charger on the controller, which takes longer to charge but gives more run time than a bit char-g.
On the other hand, the rear steering makes the car steer very sharp and gives it a squirmy feel. And iracers are pretty much non customiseable, as well as digi-qs (the bodys are permanently mounted onto the car) An ir controller also produces some lag in control.
Overall: 8/10
The car is great, but the fact that you cant change the body or motor can make it a bit dull after a while. I-racers are much cheaper than Digi-qs, an iracer only costs $20 at toys r us while the average digi-q is $40.