Okay, I am in the exact same boat as you. I know this is two years too late. And I also didn't take the time to read all of the posts....but I'm also having a hard time deciphering the difference between infp and ISfp. It's bothering me...not because I want to know which one I fit into but because I dont understand the difference. I read a comment that said infps have fe which is extroverted feeling. But i know that's not true because I've read multiple places that infps have introverted feeling and extroverted intuition. I beliebeve isfps also have introverted feeling. Sometimes when I take the test, my N scores extremely high. Other times, I get S. I know I'm not contributing new information here. I guess I'll keep searching.