There's something else... all Schuko outlets I've used so far look a lot more substantial and take up more space in the box than anything else I've ever wired, that is French, Italian, Swiss, BS1363. Judging by the pictures I've seen NEMA sockets seem to come close to Schuko.
Of course some cheap Schuko outlets are pretty flimsy too, but it's just weird only to have a cover plate with some flimsy looking guts permanently fastened to it... Even the equally deep recessed French outlets take up much less space inside the box (I installed a few Czech receptacles since we have a house very close to the border).
