For me, blood chokes are very relaxing, even pleasent. If they are extremely tight, the pressure can hurt, but if I am in a triangle that is not perfectly sunk, often I just feel a little tired. As I struggle, I feel more and more tired until I just sort of drift off, almost as if I want to. At this point, I tend to have either figured out to tap as I go out, or my partner has decided to let go. I have never been out lying on the mat, but a couple times a training session, I will come out of blood chokes dazed, confused, and calm, staring off into the distance without fully understanding what is going on around me. Probably a bad thing, but I always seem to overestimate my ability to escape. With throat chokes, I have so much time to think about how I can't breathe, about how much it hurts, that I tap out and just am in pain, but I'm never mentally effected.