to me the "good hard data " is the shot picture one gets from experience
to comment on posts from several others
since i dont know cte my suppositions could be way off base
there is no offence intended and im sure i will be corrected..

im not sure if the shot picture is the same as stan"s "visual objectivity " or not
i do think the "visual subjectivity" is the feel part (since sublective to me implies "intuiton" or feel
as for patricks question of the "fudge factor" when the shot is alittle thicker or thinner than the fractional aim points
i think is the feel of the shot picture learned for the angle involved telling you how much thinner or thicker
in ghost ball when lined up its your built in shot picture that tells you "it doesnt look right" and if you are smart you get back up and try to aliign correctly again
i think if we all try to be jedi's and go with the force
there will be no fear of feel..........:thumbup:
what i think aiming systems do is get people to find the contact point in a quicker way than pure experimentaion
just like kicking systems get you closer to where to aim on the rail to make the cue ball go the number of rails and end up where you want it to
then its a matter fine tuning it so you are right more often than wrong
sorry for the long winded and maybe alittle off topic post....

jmho
icbw