Vantaggi
Saint-Gobain is a large, multi-national French company. They're breadth of businesses affords tremendous opportunities for career development, if you are multi-lingual and willing to relocate. Saint-Gobain is diverse enough in their product offerings to weather changing economic conditions. They are also a leader in the green technology space, which has positive upside for sector growth.
Svantaggi
Unless you are a French white male, your prospects for professional development are significantly limited. The management team does not listen to employees and poorly communicates strategy. The executive team rarely gets in front of employees, probably partly out of an elitist attitude. Technology (systems) are usually not connected, so be prepared to have to constantly re-key data - since their IT infrastructure is poor. Finally, change happens VERY SLOWLY at Saint-Gobain.