The larger sensor requires a longer lens to achieve the same framing as a smaller sensor. Since DoF decreases with FL, the larger format shows less DoF than the smaller one in the final image (for the same print size). The difference in DoF between 35mm and 1.6x just happens to be roughly 1 1/3 stops. So the 1.6 equivalent to a 50mm f/1.8 lens is 31mm f/1.1.
"Better" comes in if you want shallow DoF. You can get shallower DoF with 35mm than APS - there is no equivalent to most fast lenses, DoF-wise (like a 30/1.1).
