I've been asked about the quill length of the new Nitto UI-2 stems. It measures about 78 mm from the top of the quill to the minimum insertion line. This is slightly shorter than the quill of the Pearl stem, but since the UI-2s I received have a 90-degree extension, the clamp still winds up higher.
This photo shows the two stems side-by-side:
Here is the same view with a rod showing the height of the clamp of the UI-2 stem:
Another view shows the approximate installation angle: