One of my two best friends from college is an INFP. He kind of out-INFPs me as far as being more introverted and more feeling than I am. Getting him to talk about things can be like trying to get blood from a turnip; he requires a long of hanging out time before he feels sufficiently in-sync to share (that's a quality I have, too, but he turns it up to eleven). He also doesn't have the same technical bent that I do, which occasionally surprises me. He can be frustratingly passive about things, which is a shock to see it from the other side — I'm not exactly an aggressive go-getter in many respects.
On the other hand, we tend to naturally give each other plenty of space, not worry when we fall out of touch and to be very flexible about adjusting to unexpected changes. It can be a bit of an uphill battle to plan or do things, but we tend to be very accommodating and understanding. I know he will always give me the benefit of a doubt and meet me where I am, friendship-wise. There's also a sense of easy communication when we do finally talk about matters of import. We both have a similar sense of that constitutes "important," even if our lives are fairly different.
I can't say I've ever been particularly attracted to or dated anyone I know is an INFP. I would imagine aspects would be great and aspects would be highly irritating. In some ways, it would be similar to life with my partner who leads with Si and Ti (yes, that doesn't fit the model). I usually end up having to be the practical and organized one, which continues to be a stretch for me. In some cases, practical things don't get done in a timely fashion.