The downside? They’re expensive. Like, really expensive, depending on which one you get. Whether you really need one depends on your budget and how you’re going to be using your ball. For example, I use official match balls for practicing freekicks because they fly through the air really nicely. However, I don’t use them for training because if I lose my ball I’ll be set back $100-$300.
When it is about quality, these are almost same as premium match soccer balls but obviously not the same. To be exact, you can say official match soccer balls are positioning between premium match balls and training soccer balls regarding quality. That means these balls also offer an excellent level of air retention, shape, water absorption, curve, and performance. Although usually, they are not as durable as training balls but as a whole, they are very much durable.
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.