I'm afraid I lack specifics, though I think I can safely say "very slow." The endmills being used are also extremely small - roughly 1mm in diameter. The mill is currently being used to cut things out of small pieces of birch ply, which it does extremely well.
Edit: I should also specify that the mill in question is
tiny. It's actually significantly smaller than the computer attached to it - and the computer isn't a large one. I think it has a travel of 4" or less in all three axes.
Osage orange looks like a really nice option - it appears to be extremely dense, and should give a nice, smooth finish. Also, it's very cheap, which is, in my view, a major bonus.
Has anyone here tried milling stabilized wood?