You'll really stimulate each other at an intellectual level. Somehow, your minds will click with each other, and you'll both be able to add something of value to the ongoing conversation. You'll enliven each other's ideas and you'll both feel easy and free about saying whatever you're thinking.
Whenever you have something to say, whether it's important or incidental, you'll know your ideas will be received well. And even if you two disagree and get into an argument, it will be a constructive discussion, not a destructive mess. Because you'll both know you can be as up-front as you need to be with your thoughts and feelings, you'll both become more self-confident through the course of this relationship. You'll help each other develop strength and presence that you'll be able to use in other areas of your life, not just this relationship. But within this relationship, communication will be a strong point of your connection, and you'll rarely put each other down or make each other feel small. Even if there's competition between you, you'll see each other as equals and go head to head as such.