Race-day tires are one of the most worthwhile ways to upgrade your bike. Not only do quality tires reduce both aerodynamic drag and rolling resistance, which means more speed for less effort, they also provide a modicum of comfort—not to mention, they help keep you upright on your bike.
Remember: Never inflate your tires to the maximum number listed on the tire sidewall. The optimal tire pressure depends on your weight, the width of the wheel and your comfort vs. speed preference.