I was thinking about how there can be ISFJ-ISFJ or INTJ-INTP or other similar type relationships, and how that works for some people, but other people have more success with a partner of a somewhat different type. So here is my line of reasoning regarding that.
There are some aspects of each personality type that probably could be viewed as "weaknesses" or areas of growth towards a more balanced individual, or at least necessary to relate to people who are different (type-wise) from you. In romance, seems to me like people who are either naturally more balanced in type preferences or who have worked on these areas of growth in themselves, often are more successful in relationships with people who are different from them.
But people who do not see these traits or mindsets as areas of growth - maybe even see this as the best way of experiencing the world, or way that makes the most sense - are more successful in a relationship with someone of a more similar type to them.
What do you think? Are you more successful with someone more similar or more different from you (in terms of MBTI types)? What factors contribute to that?
Of course there are soooo many aspects of compatibility: interests, values, beliefs, etc. Just talking about MBTI here.
I have a bit of a different perspective, perhaps. I think it is very difficult to answer these questions exclusively based on personality type. I tried to keep my thoughts just to MBTI, as you requested... but they kept wandering. Every response I have seems to revolve around age each time I try to consider these questions that you have asked. I think when we are younger, we tend to be more tolerant, open-minded, and actively seek out differences in others and in the world. Often we are drawn to experiences and people that vary greatly from our own persona and comfort zones. It can be intriguing and exciting to meet someone at a young age that is unique and reveals or represents traits and views not previously encountered. Relationships between two very different personalities can ultimately end up where both persons grow and develop enough where those differences end up balancing, blending and enhancing one another over time....as long as communication and respect remain the focus.
However, I think most of us eventually reach a point later in our lives where if we aren't already in a relationship (or are starting over) and this early foundation and groundwork isn't yet established or already in place....it makes it hard to be as accepting and willing to stretch and contort ourselves into ways that wouldn't otherwise be necessary for a new potential mate. At this stage in my life, I have no desire to be with someone that I have to continuously change for, feel guilt and shame from, apologize frequently to, or be uncomfortable being around because I am inherently different than they are. I don't want to explain or defend my reasoning on a perpetual basis. I think if you meet someone, and you are both young enough and willing to put in the time, energy and effort needed to be with someone that is vastly different than how you are naturally....then that can and sometimes does work out to be an amazing relationship.
At some point I realized that what I want and need now in a relationship is acutely different from when I was younger. I am much more interested in someone who will compliment and not blatantly contrast who I am. All relationships require compromise to be successful. There will never be someone that you don't have to adjust or tweak a few things for, but asking for or demanding a complete overhaul is something else entirely. Finding someone that accepts, understands and is capable of maintaining the same stride in life, is ideal to me; more specifically, a relationship where the other person is not always running ahead or in a different direction and then stopping and resentfully tapping their foot until I've caught up, insisting I leave my own path for theirs. MBTI has helped me a lot with this and even though I believe people are more than their personality type, I can confidently say that there are a several types I will avoid having future relationships with. Typing, despite its limitations, is a great tool to help gain perspective and insight over what we need to work on as individuals...as well as help us identify what is most imperative or beneficial to us when selecting a potential partner/mate. I think it varies greatly for each of us as to what we find essential at each stage of our life. My needs and desires in regards to a relationship and partner are extremely different than what I initially used to look for....perhaps age/life milestones/experiences are all things to consider in addition to MBTI type and functions, when thinking about all of this. MBTI type imo is just one of the factors, but it seems to me there is no real answer to these questions unless you consider other variables as well.
Anyway, sorry I couldn't quite stick to your request and keep my response exclusive to MBTI. I realize my response doesn't thoroughly or directly answer your question, but these are the thoughts I had on the subject after reading your post. Thank you for making this thread...it's a great topic and I enjoyed exploring it a bit.