Splitting axe is designed to cut/split down the grain pushing it apart thus the thick wide V. A felling axe is designed to cut against the grain and the deeper it penetrates the more efficiently it cuts. To do this its a balancing act between weight, speed (handle length/weight/swing speed) & head profile that will slice deep & wide into the wood. Racing axes are thin yet fairly wide at the edge where its the opposite for splitting axe, it can be thinner in edge width but thicker in profile to push apart the wood. These are basic design differences between the two styles. Other factors such as scolloped sides, cut outs, phantom bevels can effect performance along with blade sharpness, smoothness/polish will also effect efficiency. But at the end of the day to chop wood one does not need to spend hours honing & mirror polishing his axe.