The primary selling point of 15.7.1 upon release was its compatibility with the latest models of the time. It offered improved support for the MQB platform (used by the Golf Mk7, Audi A3 8V, Seat Leon, etc.). Specifically, it addressed early issues with the electrical architecture of these cars, allowing for deeper coding and adaptation that previous versions (like 14.x) struggled with.
Ross-Tech generally does not host direct download links for specific old versions like 15.7.1 on their main page. They encourage all users with genuine interfaces to use the Current Release to ensure compatibility with modern Windows operating systems and newer vehicle modules.
For the most stable and official files, always check the Ross-Tech Download Page first. If you are looking for this specific legacy version to match an older cable, ensure you are sourcing it from a reputable automotive community like Drive2 to avoid malware.