I think for kayaks with bolts running through the hull and into the seat towers, using the adapter straps is going to be the better installation method. Your back band will be higher and the weight from your body will be spread across multiple layers of plastic rather than one. I originally drilled holes in the seat towers on my kayak to use the chucks and quickly wished I had not. Also keep in mind that where the ratchets connect to the back band pivots. As you ratchet the back band tighter the tendency will be for the straps to go horizontal, but keeping them pointed somewhat down from the back band will help keep it higher into the small of your back where you need the support.
