Well said. This is what I hear: the Noble has a mid scoop and the Khan has a "tigher bottom." The Khan has more mids, but I suspect that might not be because it is "mid forward" so much as it just is not scooped in the midrange.
There's also a feel difference: the Khan is smooth, even, and tight and the Noble has more give or sag, especially in the low register where you can really feel that tube woofiness. (It's not "woofy" per se; it just has more of that feel than the Khan which leans toward punchy.)