I was having a recent conversation with a ski buddy about finding the sweet spot on our skis. That position where you are the driver of your Ferrari.....We talked about body positions and I said finding what I refer to as my "attack position" gives me the greatest control over my skis. He brought up a good point that sometimes driving the knees too hard might get the? hips and entire body out of sync?additionally,? the skier might be in a constant state of rigidness. I belief ( and probably better stated)? is to make sure center mass is in it?s ideal position over the skis so as the lightest fore/aft balance changes have the greatest impact on control of the skis. I think in order to get there?.one must identify where their center of mass is when on the skis. One thought is that if boots are too stiff,? being able to get to that ideal position is at best difficult and? has the body always fighting to find its most efficient position?(skeletal stacking). The amount of ramp angle under foot also can play a role in finding this position as well. I recently as an experiment put 4 strips of duct tape under the heel of my footbed. Each strip of duct tape equals ? degree of ramp angle. So effectively, I added 1 degree of ramp angle to my foot and really like how that slight change made it easier for me to stay connected with center mass over the skis.
One experiment to see how moving your center mass around affects the control of your skis is to loosen your 2 upper buckles on a nice green run.? I would certainly not loosen the boots other than an as an experiment to see if it gives you a better sense of how moving your center mass forward impacts your skiing. With loose buckles for all day skiing, your fore/aft quickness would be seriously degraded. Then if you find you like the position the loose upper cuff allow you to achieve, search for ways to get your body more into that position. Maybe your boots are too stiff and you can have them made a wee bit softer allowing you to move your center mass into a more stacked position. Maybe trying to add a bit of ramp angle would be a good experiment.
How to tell?

My thoughts are when in my boots standing on a hard flat surface,? arms in your pole holding position, when I relax my knees, I feel like I?m equally centered fore and aft. Meaning, the pressure to the tongue and rear cuff feels equal and I feel stacked (weighted) down through my ankles. This feeling of being centered and balanced in my boots I believe is key.
I believe getting a feel for all this is the major step in understanding how such changes impact ones ability to be efficient and powerful when skiing. This is stuff that's easy to do and if you are not quite centered, you will feel some kind of difference.
For me, it's a lot more fun being a front seat driver.....
Best,
Gary