The MXC wheel is a forged mag wheel that will keep the tires in the optimum operating temperature better. This allows the kart remain much more consistent over the course of the run, as the tire doesn’t overheat and cause handling issues.
Douglas makes wheels that are supposed to do the same thing, with their SE model wheels. I’ve tested a lot of wheels back-to-back and the MXC gives the best feel. It is the most consistent, versatile, and best at keeping the tire from overheating. I’ve used the MXCs with success on cold tracks with hard tires, as well as hot tracks with soft tires.
The SE does the same thing, just not quite as well. They don’t feel as stiff as the MXCs.
The MXPs are going to be more similar to standard Douglas mag wheels. They’re fine wheels, you just will find that in high-grip situations, the MXC is going to help you out a lot.