The Womanizer Next Duo is an older model with basic dual stimulation (clitoris via Pleasure Air technology + G-spot via vibrator), while the Womanizer Duo 2 is the newer, technically improved version with more intensity levels, quieter motors and better ergonomics.quieter motors, better ergonomics and additional smart functions Journal du Geek detailed differences Technology & functions Womanizer Next Duo uses the classic Pleasure Air technology for the clitoris. Combines this with a vibrator for the G-spot. Fewer intensity levels, simpler operation. Focus on the basic idea of dual stimulation.mid-range price Duo 2 Advanced version with 15 intensity levels for air stimulation and 10 vibration levels for the G-spot Journal du Geek.improved ergonomics: fits better in the hand, flexible shaft.quiet motor, more discreet in use.additional features such as Smart Silence (only starts on skin contact) and memory function (remembers the last setting).