I find street shoes to be far less comfortable for any type of riding. The soles flex excessively, thereby placing excess pressure on the balls of my feet. With the stiffer soles of cycling shoes, pressure is distributed more evenly across the entire foot, relieving pressure on any particular point.

My commutes are typically under 3 miles, however. So, I almost always use street shoes of some kind. Cycling shoes would be more efficient, but I don't feel like carrying around 2 pairs of shoes, and the commute is easy enough.