The speed of extraction helps determine the intensity. If it's very slow it's a mild sharp pain - difficult to describe otherwise. If it's extracted too quickly that mild sharpness becomes super intense. It's an interesting experience.
The discomfort is difficult to describe. I best describe it as a cramp. We believe that the negative pressure is in part to blame, and we have filed IP on a possible solution.
I believe that the negative pressure/vacuum is known to be the cause. One obvious solution would be to replace that pressure with a solution, probably your own plasma or similar - and then you'd just need to determine the best technology to apply for the system to allow for equilibrium..