if you read the fine print, they get the 24 mph with a 7 cell.
it will be FINE for racing, but will be lapped by others with better cars. the fact is, you will probably dump a lot of money to keep up. but, as a new person, drive stock for now. when you get better, buy a modified motor, and a 3000 mah batterypack, or cells to match. i used the cheep batterypacks, and they are fine, but when you use matched cells, you WILL notice a diference.
there is a lot, to get raceready, but dont miss the concept, have fun!