My advice is to go with what came on it for quite awhile --- the wheels and tires on the Comp aren't too shabby to begin with.

Unless you are a professional racer, you probably won't notice any speed difference with 25 vs 30mm tires(5mm isn't even 1/4 inch), and the rims aren't that heavy either. Those 30s aren't exactly fat tires. But, they will ride lots better.

Get used to your new bike, and spend money elsewhere for awhile.

Specialized Bicycle Components