I just played the new Wieskopf course at Hualalai 9 days ago, so I can now compare the two.
While W.a.H. has not one but two Weiskopf-standard excellent drivable par 4's (one for each wind direction), overall I'd say they're comparable. Weiskopf has the edge in par 4's, MK in par 3's, and they're comparable in par 5's.
MK's lava has long since grassed over, unlike WaH, which is black everywhere, giving each a different feel. Both courses have width, but not in all places. The wind can lead you astray on occasion.
From what I've heard, Weiskopf is the better of the two at Hualalai.