1. ONLY manufactures in Geneve are eligible for Geneve Seal. Everybody can apply for COSC.
2. It is MUCH MORE expensive to comply with rules of Geneve Seal than COSC.
3. MUCH FEWER watches have Geneve Seal movements than COSC movements.
4. Patek dominates total output of Geneve Seal while Rolex COSC.
5. Both are NOT mutual exclusive, few Patek models also have COSC.
6. Most COSC movements DO NOT have high-end finish level while almost ALL Geneve Seal movements reach the COSC criteria. (Although accuracy is NOT a criterium for Geveve Seal)
Therefore Geveve Seal is FAR MORE desired/treasured in the industry and among the collector.