Challenging the PLAYER not the CHARACTER

James M over at Grognardia, made a post today about "Gangbusters".  In his post, he shares this observation about the scenario.  I think it neatly summarizes how "new school" and "old school" differ.

The other thing I love about Murder in Harmony isn't really about the module itself so much as about the type of old school play it (and Gangbusters itself) exemplifies. All of the clues that help the characters resolve the central problem of the module can only be found by looking in the right places or asking the right questions. There are no mentions of "a DC 15 Gather Information check reveals ..." or "Succeed at an Observation roll to notice ..." in this module. Instead, the text assumes that the players, through their characters, will try and think things through on their own, collecting information by visiting the crime scene, interviewing witnesses, and generally employing basic investigative techniques to amass enough clues to point them to other clues that might enable them to resolve the central problem of the module. Murder in Harmony is thus very much about challenging the player, not the character, which I think is an important feature of old school gaming.

This isn't new ground.  I know it's been said before, but I'm currently GM'ing a Swords and Wizardry based game AND I'm playing in a 4e game.  The cognitive dissonance between these two experiences is staggering.

I'm just trying to make sense of what's swimming around in my head.