I think I tested 4 at one point. It didn't seem to bring anything more to the table, for me. Considering, it seemed pretty similar to being an NF. Then I took the test at one point and got six. Went to personalitycafe.com to change it and I guess I had taken the test in the past and had gotten that and it was already on my profile. I had withdrawn from the INFP forum and kind of poked around this forum when I wasn't writing blogs.
It was very helpful finding out I was a 6 because it put an explanation to things. It helped me understand and hone in on my motivations for things. It helped me understand, being a w5 as well, why I withdrew from people and shut them out. It put some explanation to why I had performance anxiety in sports. When I ran cross country I ran my mile 30 seconds faster when it wasn't a race day. I found out why I went through like 15 jobs when I was younger. It helped me understand why sometimes I don't even trust my love ones. Man, it was helpful. I relate to 1's when I'm more certain, 9's when I'm more relaxed, 4's when I'm being less scientific and following my feelings, and 5's when I'm staying up late writing poetry, working on a project, etc.
I also retook MBTI and tested INFJ a couple of times. I really relate to them and like a lot of em. But, I don't know that I can come to conclusions so swiftly. I think I'm more like an INFJ with time, but am not, just trying to be. I like dreaming and really sorting out what I want to put my time into, but I also want to wrap stuff up and get stuff done. I think that's from being a 6w5 and why I relate to that mbti type.