Easy, Hammond organ drawbars. It made sounds with harmonics offered by zippers (synthse additive) and we play. Simple. Some of the presets sound good, others less so, but it's really serving the zippers. I do not have a manual - I do not need.
The sounds are really close to a Hammond organ, style B3 / C3 / A100 / L series / M series. Saturation (any aggressive) will more percussion than on a Hammond, key-click variable ... trs useful for live and studio. Emulation Leslie a little 'softphone': non-STREO, a little heavy chorus, but it works pretty well 'in the mix'. The 'ramp' (rate of change between slow and fast) is a little late.
Keyboard ok, 'palm slides' (shifts in palm) possible without damaging your hands. Worse than the keys Hammond.
I use it in a Hammond B250 complment (transistor), and jazz and blues fills the lack of aggressive attack of the real organ. (The Hammond, despite no tone wheel, the most beautiful sound.)
C'tait one of the first 'clonewheels', and it keeps well the head from above'. May be now by the last Exceeds Rolands (VK7, VK8) and Korg (BX3), but not as much as all that. Some fans say that X50 is still the miellieur (rsolument is analog, not modeling, so its a trs franc). The sound is (very) good: it's Leslie emulation is dcevant today. However, it is far from being dgueulasse.
I love the percussion, which 'poppent' trs cool and sounding for jazz and 'figures'.
Not easy to find now, but much cheaper than the Roland and Korg (I pay 400), and made the whelks as well (with small RESERVATION).