Common sense says that any surface to surface contact that reduces friction is going to improve piston efficiency, provided the air seal is not compromised. Which is why for more than 200 years air guns based on the spring piston have used oiled leather seals, thereby avoiding metal to metal contact. Synthetic seals are just a more recent variation on this. Modifying a piston to have minimal friction has been a given for many, many years, so why does a manufacturer have to introduce a new term like "gliding" , as though it is some new hi-tec approach that others have not considered? Smoke and mirrors to push sales, IMO.