No personal experience. BUT I had a lengthy chat with Troy Watson of Ligero Wheels. He raves about the quality/workmanship of Hope hubs. He says when you take them apart (for servicing), there is this characteristic reverse suction sound which, to him, speaks to the quality of the seal.
Funny you should mention the Chris King hubs .. I went with those instead
Though I suspect you'll like the Hope ones. Great quality it appears for lower price than the CK.
Edit: The Pro 3 is what I was looking at. I think in the end, it was the wait time (at least for Troy to get them) that swayed me. And I am vain and want to match the CK headset in red that I already have.