I think depends more on how great each divide is, than the type of divide. The biggest conflict I (ENFP) have with my husband (ISTP) is T vs F. Our S and N tend to balance each other out and bring new perspectives to each other. We may see things different, but we fully understand why the other one views things as they do where the T & F seem to cause more hurt feelings & frustration when we do have conflict.N. I like intuitive people.
S/N is the biggest divide, it's much harder for N's to understand S's and vice versa, as compared to F and T. at least I think so.
Ne seems to be the most obviously important function to me. I enjoy using it for myself and when interacting with other people (well, people who get that type of thing--I run into difficulties if I, say, make Ne-based jokes around Sensors). Ti--I think is more of a default thing that I'm not even aware of, so in that sense it is important to me, but for interacting-with-other-people mode, it seems to be much less successful than Ne. Si--I am not even sure if I've been aware of how I use this! I'm going to read up about it and try to notice it more in my life. Fe--:frustrating: working on this should be important to me, I know. but :frustrating:Which function do you find the most important to you? Ti, Ne, Si, Fe?