Full disclosure, I'm not a fan of the 5196 - in any metal - but I don't find it to be a cocktail watch or one to be used only on occasion. I think it's a very versatile watch, transitioning well from polo shirt to a suit and tie. Obviously not a sports watch, and need to always remain aware of its minimal water resistance.
The caliber 215 is a robust, bread and butter reference from Patek. Tried and true, and virtually bulletproof. No worries about winding in my experience, highly reliable and accurate timekeeper, used throughout the Calatrava and Gondolo lines for many decades.
So why don't I like it? A 21.5mm diameter movement is ridiculous in a 37mm case, IMO. Perfect for a vintage 31-33mm Calatrava, but unacceptable in today's offerings. Even without a display back (which Patek mercifully omitted in the 5196), the miniscule movement forces the small seconds register too close to the center, ruining the overall aesthetic.