It's a no brainer:
+Business/first class lounges, free good quality food + liquor, fast wifi, power, comfy leather chairs, no kids or crying babies
+Bonus Airmiles
+Cute amenity kits, (I fucking love these)
+Early boarding
+Free good to excellent quality liquor on plane.
+Delicious meals that were envisioned by Michelin star chefs and prepared properly.
+Comfier seats, with a lot more legroom and fully flat reclining function
+No kids or crying babies near you.
+Better treatment.
+Soft blanket.
+Networking with interesting international business men.
+Did I mention the lack of kids and babies?
It's so much better then economy.