No, no ear crop is more correct than another... but the longer, more sculpted crop is more common with show dogs, and show breeders. IMO, the shorter, less sculpted crops do not compliment the head as well as the longer, more sculpted crops.
Most crops you see on pets are pretty horrible, unless the dog came from a responsible breeder. Most vets that crop really don't seem to have much of a grasp of how ears are supposed to look!