It seems to me that the suntour blueline shifters on the Lotus Unique I used to have shifted quieter than my Shimano SIS shifters in the
friction mode.The shimano shifters shift ok but you still get the fairly loud click from on gear to the next, you just cant feel the click in the shifter.
If I remember right the old Suntour shifter seemed much smoother going from one gear to the next.