So weird they're supposed to be rare. I've known so many INTJs. But I've worked in politics and the sciences (<---typism! In action!)
My best friend in high school was a female INTJ, I currently work with a female INTJ (maybe 2), and I've worked with one before as well. I find they tend to be friendly-mannered but generally aloof as they take you in. Very intelligent, sensible and capable, with a slightly dry sense of humor. I find they highly value intelligence and competence, especially in the work place, and they will respect you and warm up when you exhibit these qualities. Additionally, while it may initially take them by surprise, I think they eventually value the special passion and feeling that an INFJ can exhibit about certain subjects. For example I used to work at a non-profit and while the INTJ in the org was competent and was committed to their missions based on her logical belief of right and wrong, I think she was curious, surprised (and touched?) at how personally I took the success of our projects and how fired up I could get/emotionally invested I was in them. I was constantly in awe of how cool and collected and competent she was and enjoyed her chill, dry sense of humor, so we worked well together as a team; very similar competencies and abilities except with the head/heart difference in perspective and enthusiasm, which may lead to differences of opinion. When I dated a male INTJ, he told me that the thing he loved most about me was how affectionate I was. So I think that the (judicious) display of your warmth is something they value in INFJs, but only after they have established respect for your intelligence. That relationship eventually fell apart however because we both thought we were smarter than the other person and could never admit we were wrong. I find INTJs don't like to be told they're wrong about intellectual things, but they will respect you and cede the point if you can prove it (thought they won't like it) and don't make it personal or get overemotional.
When my INTJ colleague took the Myers-Briggs test for work she told me she'd thought I was an ENFP because I get along with people so much better than her and seem drawn to them. I think she was a little offended at how cold and calculating the description of her was. I find that she and other INTJ women are not devoid of feelings or anything like that; it's just that they tend not to display them, or sometimes listen to them, and I think they like that aspect of themselves being drawn out by INFJs. At time I have felt that some can be a bit competitive, calculating or manipulative of people or situations to get themselves ahead in the workplace, but they are always so competent and fulfill their duties better than almost anyone else, so it is a tough point to argue. I find them very laid-back, clever, funny, and easy to talk to about most things unrelated to work/school.
So yeah, as an INFJ as long as you watch your "always-think-you're-right" tendencies (they have those too), don't let yourself get intimidated by them, and let them see your intelligence and warmth and don't push it too fast, I think INFJs and INTJs are very compatible. I have found them some of the easiest people to truly be myself around.