While neat as hell, and likely very capable, the DDG-1000 cannot perform the mission of two Burkes.
And definitely cannot be in two places at the same time.
It carriers approx 20% more VLS tubes (120 I think)for more than twice the price.
While it does carry the 155mm gun, what will that do that a 5in/54 won't at sea?
As for stealth, I don't buy it. There's no way to hide a 15kt warship.
The Zumwalt has a very different mission profile than the Burke.
The Burke is a multi-role, air defense destroyer.
The Zumwalt is a multi-role fire support destroyer.
Very different set of missions for the primary role.