I have heard both o/96 and fleetwood deville.
If I have to compare the sound of the o/96 to your soul supreme, I would say that the Zu has a faster transient response than the o/96. Zu has bit more energy in the upper midrange. o/96 has more dynamics, more bass quantity and better quality bass. o/96 has wider sound stage than the Zu. Has that Oomph factor. Has a smoother treble and upper midrange and feels like overall more balanced across the whole frequency region. Both have quite large image size. o/96 needs bigger room to breathe and harder to set up properly than the Zu.
Fleetwood Deville is a sweet sounding speaker, it has a more polite and gentle sound compare to the Zu, but has a wider sound stage. It lacks dynamics and bass compare to the o/96 but it has little more bass quantity than the Zu soul. It sounds lively but not as much as the Zu. This speaker is easier to place and set up compare to the o/96. o/96 needs quite a room to breathe and needs lot of distance between the front and the back wall + quite a bit of listening distance but Deville is more room friendly if you have a smaller space. You can listen for a long periods of time without a listening fatigue as it does not emphasize on the upper midrange compare to the Zu or even the o/96. Deville is the hardest speaker to drive compare to o/96 or the Zu because with either, you can pair it with single ended low watt tube amps but not the Deville. But it is still relatively easy speaker to drive compare to most speakers on the market. They will be fine with push pull tube amps.
I have not heard the o/baby but heard the o/93. If you have any questions your welcome.