Steinberg’s version uses the same samples and technology as Neo Soul Keys but only one instrument is available - Suitcase. NI version has Stage and Wurli pianos - that’s why it’s named 3X. Steinberg Neo Soul can be used as a separate instrument (VSTi) or inside HALion Sonic SE/HALion. You can save your own preset like in other VST instruments.
Well, I miss the Stage piano from 3X 
I hope Steinberg decide to release its HALion version as well…
Regards,
Jacek