Kompany's not ready for the role.
When he settles his game down, he'll be ideal, but not at the moment. He plays well more than he doesn't, but I don't think he's 'captain' material, right now. Zabs is more consistent and a better choice. He doesn't stop running, gees up his comrades and shows passion.
I'd like to see Neds with the armband in 5 years, but also think he'd make a great vice cap, if Zaba was the captain.
*btw, I don't mean next year. The season after.*