So far their designs have been fairly conservative, but they've made some pretty significant advances in manufacturing process and in materials as compared to their rivals, despite their designs being relatively similar. Heavy use of friction-stir welding would be an example of the former, and the PICA-X heat shield material would be an example of the latter, and details of the former (if you watch SpaceX factory tours on youtube, etc.) are considered trade secrets that aren't shown to the public, even though they're not patented.