Specific examples of differences in manufacturing between Rolex & Patek/Lange?

[daOnlyBG]

Hello all,

I often hear that Rolex watches are (at least in relative terms) "mass produced," whereas brands under the "haute horology" label (i.e., Patek Philippe, A Lange & Sohne, Vacheron Constantin, etc) are "handmade."

It got me thinking- besides the ornate aesthetics on the movement, is this... true? Is there really a difference?

I figure that like Patek, Rolex employees assemble the watches by hand and adjust them accordingly. Like Patek, those parts are probably made with machines and inspected at the human level. Do Patek's employees spend time filing/fine tuning the parts individually, whereas Rolex just puts them into the watches?

So the question is: what specifically does Patek (or Lange, etc) do in their manufacturing process that justifies classifying their watches "hand made," as opposed to whatever Rolex does?

Thank you in advance!