The reason Haye is a heavyweight contender is due to his hand speed, reflexes and power. He's still got a lot to prove but no one can get close to him for hand speed.
Chambers is still a better boxer than Haye and if they fought, most likely Chambers will outbox Haye. Chambers skills are on par with the Klitschko brothers imo, maybe the Klitschko brothers are slightly more skilled. Also unlike Haye, Chambers is willing to fight Wlad and will not back out of a fight.