I'm so glad my sensual + energy flow description makes sense to you given your experiences. I too can sometimes feel a little tension between the two as well - just as you said, that would be being too much in my head and not enough in my body. For me what works if that happens is ... well, I actually don't know exactly. I kind of feel like there's just this zone of sensual experience + energy flow that prevents being too much in my head, and there's also a space that encourages it. I'm not sure what makes the difference for me, and am going to think more about that.
(and I don't remember that "too much in my head" thing happening with the ISFP. Even the one negative experience we had was at the energetic level, and I didn't feel trapped in my head away from my body at all even then. And speaking of music, she had this awesome sound system in her place, perfectly set up for maximum quality and acoustics, and it was always on. I think over time that constant music would have irritated me. But for the time we were together, it was wonderful. So when I think about being over at her place, I remember that there was this gorgeous music playing all the time. But at my place it wasn't there, it was just quiet, and we still had the flow so it wasn't the music specifically.)
Oh, and when I was writing the previous comment, I had this vague pinging on how Si might also be involved with my INFP somehow, but I can't quite put it into words (and am picking this up from the outside anyway).