High magnification: 1.5× means you can get more detail than standard 1:1 macro lenses. Good for very fine detail work.

Working distance: At ~14.8 cm in front of the subject when at 1.5×, fairly generous compared to many shorter macro lenses. This helps with lighting and working with live subjects (insects etc.).

Apochromatic correction: This helps to reduce chromatic aberration (both longitudinal and lateral), which is often a problem with macro lenses. Should give better color fidelity and less fringing.

Relatively lightweight & compact for what it offers (180mm tele macro with 1.5×). Makes field work more practical.

Versatility: Because it’s long focal length, can double for certain telephoto / portrait uses (though f/4.5 is a bit slow for very shallow DOF in that focal length).