Hasselblad’s main advantage over high-end Canon/Nikon DSLRs is medium-format image quality, not speed or versatility. Compared with 35mm full-frame systems, community answers point to:

• larger sensors with higher available resolution
• very sharp optics across a larger image circle
• modular systems, with interchangeable backs and finders
• some Hasselblad-specific features, such as focus systems designed to reduce focus-and-recompose errors
• on some models, 16-bit files and no anti-alias filter for maximum detail

In practice, that makes Hasselblad most attractive when maximum detail and image quality matter more than responsiveness—typically controlled studio, fashion, product, commercial, or landscape work.

The trade-offs are significant: these systems are generally slower, larger, less suited to high ISO, often less feature-rich for action shooting, and may have limited autofocus and weather sealing compared with flagship Canon/Nikon bodies.

So the reason to switch is usually simple: you need the highest image quality and system modularity that medium format offers, and you’re willing to give up speed, portability, and low-light/action performance to get it.