I have looked on Nashbar and Performance Bike at their various inexpensive bicycle shorts and see a lot of reviews complaining about various aspects of the clothing. Since I am obviously a clyde I figured it would be better to ask here since the responses would be from folks built more like I am. I am hovering at the 230 mark right now.
Anyway, my commute (which is mostly what I would be wearing them for) is six miles one way when I take the most direct route. I have an alternate route that is closer to twelve miles that I sometimes take on the way home.