i have not tried the super down... have the kenai and kifaru lpp... for me, the lpp is the perfect puffy, it's wet here so down isn't ideal, and the durability of the lpp is great... you'll have to decide what is the best fit for what you do. when it's cold and windy, sitting up on a high ridge set up glassing for hours, the lpp is awesome, it's like putting on a sleeping bag... i trade the bulk and durability and wet weather performance for the pros of down.
if i spent a lot of time in really cold dry climates, i would have a down option too, but it would be in addition to, the lpp's durability shines for me, and i like the front pocket design when wearing my pack... like everything i own from kifaru, it's a well thought out piece of gear, and perfect for the coast