Over time, many soccer balls tend to go out-of-round, especially if they are well-used. The Glider is designed to maintain its shape without losing air thanks to the firmness and consistency of the butyl bladder. Under regular use, we found that the air pressure was consistent enough that we didn’t need to add more air to the ball. If you play in organized soccer, then having consistency from the practice ball to the game ball is very important for skill development. The machine-stitched panels offer that experience for most players, even though the ball has the standard panel design.
On the other hand, replicas (sometimes called training balls or gliders) are designed to be just like the official match balls but are much cheaper. Their panels are often stitched rather than thermally-bonded and are made of a different material. However, they’re not necessarily less durable than official match balls. So, they’re the recommended option for most players. https://www.youtube.com/watch?v=j2Xn84L3Kcs