I would like to challenge the commonly accepted view of "sensitivity" and differentiate between sensitivity as pertains to actually building arousal
and sensitivity merely indicating touch awareness
. I am pretty sure not every nerve on the penis has an erogenous purpose, and whether arousal will build or not (and eventually culminate in orgasm) will further depend on the kind of touch that is registered and processed by the brain.
So, by that rationale, I would answer the question as follows:
1. upper part, underside, and sides of glans, very responsive
2. corona along entire circumference, very responsive
3. inner skin layer behind glans, somewhat responsive
4. meatus and shaft skin, barely responsive
And that makes sense, because the two under point 4 are "designed" to have outside contact even in the uncircumcised penis.
Now, as for the kind of touch:
I believe we can subconsciously distinguish between controlled, intelligent touch with human intention and mere, physical contact. The brain makes that distinction for us. And that is why there will always be more arousal from a hot Moroccan super model resting a finger tip on even the least sensitive part of my penis than there ever will be from a sock falling on top of the glans.
And this is where, I believe, all the poor intactivist sods mourning their foreskins are setting their own traps, because they are accepting mentally that there can be no, or only little, stimulation, essentially switching off their own pleasure approval centre. They are creating their own, self-fulfilling prophecy. And we don't.
It has nothing to do with the thread, but I simply have to voice my longstanding observation that the difference between circumcised circ fetishists and circumcised intactivists appears to be the same as the one between the proverbial "glass is half full" and the "glass is half empty" sort of guy. Only that in this case, the brain will actually contribute to "filling the glass." I think we should congratulate ourselves on our constructive positivity.