Cottonwood in IN
Same thing here. Me and dad had some cut up some on a wood mizer a few years back, and i think i threw the last of it in the burn pile a few months ago. It is almost imposible to get it to dry flat, and even once its flat, it waprs very badly. And its like you said, once its dry its very brittle. Plus, it gives a foul odor as you mill it, cut, drill it..anything!
Our intent was to use it on cabinet backs, and drawer guts, and any place hidden, but it was just so unsightly and warped, we didnt use it.
Its just me, but i would skip over the cottonwood, for anything except carving, or something like that.
Now I use ash for hidden cabinet wood.
Matt