Fred,
I'm a "Hammond snob" from way back, and all I can say is ......... the Leslie is more than 1/2 the sound. I've had Yamaha TX81z modules sound "right on the money" when played through a Leslie speaker. The Yamaha fm synthesis produced sine waves that were as pure and acurate as a real Hammond......... all that was missing was the percussion and the grit.

Unless the X5 had digital samples in it
(I don't know the model, sorry), I'd look for the new digital models by Hammond, Roland or Korg and get a real Leslie or Motion sound rotating horn cabinet.
They all sound and feel just like the real thing when played through a rotating horn. It's the air movement that "makes" the difference.