Nod units are better. But the sedan is good for snipers that want to go somewhere quickly, then hide the vehicle (or destroy it).The Chameleon as stated before is excellent for squishing infantry. It's also better armored then the nod apc and harder to hit since it's low to the ground. A good replacement.
The mutants are also good. Since they can heal in the tiberium, and the one mutant is the faster infantry in the game. (the one with the auto rifle)
the code to unlock this isn't a cheat though. So don't say it is.