I prefer the darker version. As to the range from black to white, it seems that the banister on the left is your brightest object. I think that the subtlety of tones in the railing, and the darker forms bring out the drama, and that arbitrarily making the blacks 0,0,0 and whites 255, 255, 255 might satisfy some abstract requirement of what a B&W image should have, I think it would be overkill and drown out the depth of what you have here.
I also think the highly graphic composition really works well.