Having used an IBM XT keyboard for a bit, I can't help wondering if the BAE is a sort of "missing link" between that layout and the Model M. It seems like if you were trained to touch-type on the XT, then you would naturally reach your pinky finger way over to the vertical part of the BAE, and if you were trained on the Model M, then you'd naturally reach for the lower half of it. Either way you're good.