Hello,
The idea of the simplicity, as I understand it, is to leave all the "fun" stuff (complications like the chrono, tourbillon, ...), and focus on the basics : Hour, minute, seconds.
But Dufour puts so much attention on these basics that he (tries) to achieves what is the closest to perfection.
He takes no shortcut.
On the route to perfection, every step you take is harder, longer, and more expensive. Like climbing the Everest. The higher you go, the heavier your steps are.
Most of the high-end companies (Patek, Lange, ...) stop a few hundred meters from the top.
Dufour chose to go a little higher.
I guess that to a beginner's eyes, there are no visible difference between a Patek and a Dufour. But for the Pursists right here, there are.
AS I'm not a owner of a Simplicity, this is only my thoughts and feelings. I'm sure a owner will be able to give you more info.
jjcasalo