Birch P

I am considering replacing my current frame bindings (marker duke) with either this or shifts in order to make touring more efficient without giving up on safety and performance. I have a couple questions to see if this binding might be the right fit. First off, how is the the vertical elasticity / retention at the heel? I tend to pre-release at the heel when I ski hard, especially in heavy snow, so I am wondering if this heel-piece would suffice. I weigh 155 lbs and have found toe dins of ~8 and heel din...