twin tips initiate turns easier and make possible to land switch, but the really fuck with the swing weight, they also do not hold the edge in the tail as well as a traditional flat tail. the squared tips and tails direct more pressure to the ends of the ski than a traditional rounded tip and tail would (not really significantly tho), but the noticeable difference is swing weight. squashed tips and tails are simply easier to spin
probably brand identity as well, but main difference is swing weight