I wish we knew how things turned out with Skylar and Flynn and Marie. And, a minor flaw - in the shootout scene, the redheaded guy shot at Jesse 5-6 times from not-far-away, and didn't hit him even once. I guess Jesse still has both sides operating in him: the sweet-Jesse-side that cuddles insects, and the Walt-protege-side that blows up dead bodies to hide evidence.
But overall, it was great to see some of the old characters.