A Backcountry rep and Sessions customer service, Product Development dept. and Marketing dept. all said that these shorts are supposed to fit like compresson shorts...tight, body hugging fit.
I tried out two pairs of mediums and a small and none fit like compression shorts. The leg openings and body of the shorts are somewhat loose. The fit is true to size, so buy your normal size and disregard the sizing chart.
I couldn't even tell I was wearing padded shorts when I recently went to the mountain. I haven't crashed yet, so I can't say how well the pads protect one from injury.
Bottom line: Though I was expecting a compression short type of fit, these shorts are actually really comfortable and the padding is really low profile so you can't even tell you're wearing impact protection.