re: pressure on 1 spot

I haven't used any of these products.
An an EMT, the traumas that I have treated I treated with piles of 4X4's held tightly in place with Kling wrap gauze. This applies a presure over a 4-6 inch area and seems to work well for most venous bleeds. I haven't stopped an arterial bleed yet. If you have a 4 inch gash and you put pressure on a 1/4 inch area you haven't put pressure on the wound - only a part of it. Further, if you have an bad bleed you need to slow blood flow through the effected area so that it doesn't flush any clotting that might occur. This is not a tourniquet but simply holding the flesh closed tightly enough around the wound that the blood flows in the vein rather than out of it. This will be difficult but requires braodly applied pressure. Usually pressure area about the size of the palm of your hand is helpful. Pressure area the size of your finger-tip will do little to help. If a pressure area the size of your finger-tip would help then you probably don't need anything more than a bandaid.