There will be a very comforting sense of stability to your connection. You'll know where you stand with each other, and that counts for a lot. To your friends, you may seem a bit on the serious or predictable side, or outwardly unaffectionate as a couple, but you'll both appreciate the feeling of steady trustworthiness that permeates your bond, and you'll both feel confident that this could last a long time if you want it to.
Even if life seems hectic or chaotic when you're apart, you'll feel safe and grounded when you're together. You can have a very positive effect on each other, in fact, especially if one or both of you tends to be overly impulsive in any way -- emotionally, materialistically or otherwise. You'll learn a lot from each other and become much more mature and restrained through the course of this relationship. The only problem is, you might become too comfortable within the limits this connection describes -- in other words, you could easily get stuck in a rut together. Try to challenge yourselves on a regular basis to experience new things together and think outside the box, even if it's something as simple as trying a new restaurant. Don't forget about growth and flexibility, which are every bit as important in a relationship as stability and durability.