I think I know the answer to this, but hesitate nevertheless and would be grateful for some advice.
I'm 5'11" and a very overweight 209 lbs ("normally" 170 lbs). Four kids, etc ....
Years ago (when I was at my "normal" weight) I chose the Kastle MX 78 as my "one-ski quiver" for New England conditions, but in a very short 168 cm in order to tighten the basic TR (though still a GS-like 16m). The MX 78 has been wonderful, though wasted on me for years — because it was not until this year that I finally started to really "get" carving.
In fact, just this past week a passing skier yelled out "That was awesome!" after a particularly tight and "rhythmic" run, something no one has ever said about my skiing, even when prompted . Exciting stuff!
Unfortunately, nowadays I have been relegated to shepherding my little kids (<= 9 yo) down green and easier blue slopes. I would like to squeeze in as much practice as possible by increasing the frequency of my turns and perhaps also reducing my speed. The MX 78 loves to go fast ....
Now, the question. Back in 2012 I demoed a X-Shape STX (sans KERS) in 170 cm and that was the first ski to introduce me to an edge. My demo notes from that era gushed gratitude.
It's not crazy for me to consider purchasing a Head Supershape e-Original in 170 cm (or even 163 cm?) to avail myself of its tighter 12.1m TR, just to help me accelerate my training, is it?