All four share the same frame and the same dynamic support system.
Omni SE is the manual build: a rotary lumbar knob with 40mm of travel, no battery (so no OmniStretch), and a single finish, Obsidian. It offers 5 recline positions (105°, 115°, 125°, 135°, 160°).
The original LiberNovo Omni is the electric model that started the line, with a 50mm electric lumbar actuator, one-touch control, and 4 recline positions (105°, 120°, 135°, 160°).
Omni Gen, the upgraded generation, retains the 50mm electric lumbar adjustment while adding 5 recline positions (105°, 115°, 125°, 135°, 160°) and more adjustment flexibility.
Omni Pro also offers 5 recline positions (105°, 115°, 125°, 135°, 160°), plus Active Airflow seat ventilation, a die-cast aluminum base (vs. glass-fiber-reinforced nylon on SE, Gen, and the original), Gabriel Atlantic fabric, and a larger 3000mAh battery (vs. 2200mAh on Gen).
Choose SE if you'd rather set lumbar depth by hand with no battery to charge, the original for core electric support, Gen for the latest adjustability, and Pro for Active Airflow ventilation and premium materials.