DoF calculators do not take lens quality factors into consideration. My experience is that many lenses are quite poor at very wide apertures of F2 and wider.
I don't know how the Canon 35/1.4 rates at F2, but at F1.4 it seems worse than the cheapest lens (at f8) that money can buy. At 10 lp/mm the MTF graph never rises above 80% and at 40 lp/mm never rises above 40%.
The usual counter argument is, you don't use wide apertures to get crisp resolution but to get shallow DoF.
My argument would be, if you haven't got crisp resolution at the plane of focus, you haven't got the shallow DoF that the DoF calculators would imply.
To take an extreme analogy, pin-hole cameras produce great DoF, but the images are not sharp anywhere.
Perhaps I should add, I've excluding esthetic considerations from the above comment, such as niceness of bokeh.