This will explain the difference between the Srixon Z-Star and the Z-Star XV.
The Srixon Z-Star and the Z-Star XV are the top performance golf balls from Srixon. The Z-Star is slightly softer and is designed to get maximum spin and touch around the greens (similar to the Titleist ProV1). The Z-Star XV is a harder golf ball, so it's designed to maximize distance while still offering great touch around the green (similar to the Titleist ProV1x).
The Srixon Z-Star golf ball maximizes spin and touch around the green, and offers great distance. The Srixon Z-Star XV golf ball maximizes distance, and has great spin and touch around the green. , The difference between the Z star and Z Star XV golf balls from Srixon is feel and spin. Srixon Z star is going to have a softer feel and offer more spin, while the Z Star XV is designed for faster swing speeds. , The Srixon Z-Star XV will produce lower driver spin while maintaining high greenside spin. The Z-Star is generally a higher spin golf ball which will promote even more spin control near the green.