Oh, that's nice to hear!
We are growing chestnuts. Very early days yet, none of them has fruited, and given our climate (Norwegian coast) we'll probably have to wait for a decade or so for nuts, but they are growing quite well. As for what species we are growing, we've just collected nuts from trees we came across, mostly without known pedigree. Most are probably C. sativa, some I strongly suspect to be crenata x sativa (one lonely small tree with very big nuts in a garden, with plenty of wild-ish sativa trees in the vicinity) and a couple are either pure dentata or dentata x sativa (nuts from a couple American chestnut trees in an arboretum, in an area where there are wild sativas, although not in the immediate vicinity). We're taking a "landrace" approach to chestnuts, plant them all together and let them cross freely, growing out nuts from the trees that do best in our area (if they ever manage to fruit, that is...) Would like some of the other species too, if we can find them, to increase the genetic diversity further.
I just read something interesting
here. Apparently, some surviving trees of C. ozarkensis, the Ozark chinkapin, have been found to have even better resistance to chestnut blight than C. mollissima. Now that would be some nice genetics to have in the population! Can probably just forget finding any on this side of the Atlantic, though...