Props generally have a lower "image factor" than jets, meaning that they will get lower load factors. (every airplane has an image factor. older/smaller/"unreliable" popular image makes it lower .. etc.) Also, props are slower, and faster flights tend to get higher LFs.
However, Props are so efficient that the lower LFs are usually worth the savings in fuel and maintenance, although it gets iffy once you get to planes with less than 50 seats.