Unlike low-quality soundfonts, these libraries offer velocity-mapped multisamples for realistic playing dynamics.
Honesty is the best policy. The is technically abandonware in most circles. Roland Corporation has not re-released these sounds officially for KONTAKT (they have their own cloud subscription, Roland Cloud, which contains the Zenology engine that emulates the Fantom X). Roland Fantom X Complete KONTAKT
One of the largest versions at 8.56GB, praised for its "high quality" and faithful recreation of the hardware's stereo image. Unlike low-quality soundfonts