Pecan is pretty high on the Jenka hardness charts. Not many American species are harder. I've never milled Mesquite, though. How big does that get? I thought it was pretty small stuff.
I mill mostly pin oak, silver maple, ash, cherry, and walnut, but have also milled white oak (as much as I can get!), sugar maple, hackberry, box elder, walnut, hickory, pecan, cherry, hackberry, honeylocust (my favorite!), black locust, mulberry, sweetgum, sycamore, sassafras, tulip, white pine (never again!), and some unknown stuff.
Honeylocust is amazing - that stuff will practically dry flat without any help at all, and is really easy to work with.
Box elder is great with the beautiful red streaks.
Walnut is king, of course. Very stable, very beautiful, great to work with.
Nope. Not that I recall.