Ideally I believer the opposite type should be the type that has the exact opposite of your functions, not the type which has your functions in the reverse oder. So if you are an INTP your opposite type should be Te, Ni, Se, Fi (ENTJ) as opposed to the type that has your functions in the reverse order which is (Fe, Si, Ne, Ti) ESFJ for INTP because the former type has NO functions similar to yours.
Hmm.. now come to think of it, a person with reversed functions might have reverse priorities because the way they take in information (coginitive functions) are completely different to that of yours.
How about the type which not only has no function similar to you and these functions are in the opposite order. So that would be ESFP for INTPs.
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So I'll cover my experiences with all three types assuming I am an ESTP. That means INFJ, ISTJ and ENFP.
INFJ - great. I find them to be awesome buddies. They are loyal, friendly, warm, well read (I think they are only second to INTPs in their reading enthusiasm, unless we are talking about INTJ e5s) and dependable. I like the word dependable when measuring friendships. Dependable and socially compatible are what I look for in friends and on those rare occasions someone who is extremely different to me but can help me grow as a person.
On the negative side, they kinda ride of ride a high horse and have sensitivity issues. However, you'd only be negatively affected by their high horse syndrome if you get too close to them.
INFJ males I have noticed are off their heads. Yes I was talking about INFJ females up there.
ISTJ - These guys are the best. Dependable, loyal, does not have sensitive issues, no drama at all. On the negative side, they are kinda cynical and negative. Awesome story tellers too they are. Gives good practical advice when asked for. I could imagine myself settling down with an ISTJ e9 So dom.
ENFP - They could drive you nuts since they are so disorganized and this also makes them less dependable. They have one redeeming quality as friends, they truly try to understand you, don't try to change you (yes that is awesome) and try to bring the best in you. These happen usually in bursts, not planned well thought out conversations. Ethical too.