If you’re going to race, get racing shoes. Less weight on your feet lowers your oxygen cost at a given pace, which should translate to racing faster.
The problem people run into with racing shoes is muscular fatigue and soreness, during and after races, usually in the calf and Achilles areas. That’s a consequence of the shoes typically having lower heels and less cushioning than training shoes. Easy solution: wear your racing shoes for your hard workouts. Doing so prepares your muscles and tendons for the slighter shoes on race day. Wearing your racing shoes in training can also help you run those hard workouts faster and with the lighter, more efficient form you want when running faster.