Emotional issues are not easy between you, because you really have different emotional filters through which you experience the world. What makes one of you laugh uproariously makes the other uncomfortable; what makes one of you cry may seem minor and insignificant to the other. This kind of emotional disconnect affects your relationship on so many levels: It can make it difficult to choose a movie to go see together, because you have different tastes, but it can also make you feel like strangers when one of you has a problem that the other just can't understand, or when one of you just wants to joke around and have a good time goofing off together but the other is in a serious mood.
Part of the problem with this aspect is that over time, you'll both start to feel like you're really different from each other. Emotional disconnects have a way of coloring everything about the relationship; even if you do have some common interests, you'll both start to feel like strangers after a while. If the relationship is important to you, you'll make it work only through putting real effort into accepting the fact that this person is just really different from you on an emotional level, and you can't expect to have the same emotional responses to everything that comes up. If you can do that, you'll probably both start to appreciate your differences -- your emotions could even end up being complementary.