I use a comparator to identify my headspace with the bolt disassembled. I then use the same comparator to set the desired shoulder bump when setting the sizing die.
Me too, use a comparator tool on my verniers.
In my early reloading days, I would set my sized cases to have a half fall of the disassembled bolt, this was often inconsistent.
Getting consistency among your reloads is key for accuracy and dependability if done right. Using the "feel method" is alway going to be less consistent than a comparator. There isnt a neuro-sugeon in the world who can "feel" .002 difference when closing a bolt. So its always best to use a tool capable of measuring down to the thousandth of an inch to compare your fired case to a resized case. Achieving a true -.0015 to -.002 will yeild the best results for most and there is just no way to do this consistently using the "feel method" .