I understand where you're coming from, and I sometimes wish it were possible to reduce an entire personality into four letters - "This person is ABCD, so they work well in groups of such a size, need their information in such a format, &c" - but the reality is that a person who conformed absolutely to their indicated type would be pretty poorly-adjusted to living in actual society.

I get frustrated when I see people putting such weight on their indicators, or ascribing aspects of human nature (eg, "a messy web of thoughts") to a unique identifier supposedly held by a small percent of the population. It frustrates me because I sometimes want it to be true, but I know it isn't - not in the way they think it is, anyway. There is a lot of criticism for the MBTI.

That said, I don't think it's completely invalid. Keeping in mind what I said in my first post about tendencies vs absolutes, I'd say 75% accuracy is a reasonable figure for the descriptions found in this article) and this article (I'm using Wikipedia as a quick reference, but again, I did not come up with my type by myself, nor through an online source). I don't relate to all of it, but there are many things there which are both specific enough not to apply to the entire population, and close enough that, as you say, I felt understood.