I think this exercise points out the use of HDR over a single exposure. Your camera has about a six stop range for bringing out detail in a single exposure. HDR can be used to bring out the detail in shadows and highlights when the exposure exceeds the single shot range of about six stops. The greater the stop range difference the greater the distinctiveness of using HDR. This shot is within the detail range of the camera with just a single shot. As Cnyram has stated the differences are subtle which can be accounted for by personal preferences, the slight differences in processing by the camera of the four shots, or slight differences in the computer processing and down sizing to be posted here. Both are excellent renditions of the composition and any minor differences can be adjusted in post processing depending on your personal preferences. Which is bette? Neither, they are both excellent exposures.