In order to really improve your skiing, you need to improve your physical conditioning, improve your technique (coaching) and have the latest-greatest. It is not one or the other. When you are over 40, usually the easiest it to get the latest and greatest material. Won't give you a lot more, but won't hurt either (unless you buy several skis per season...). One thing that I have seen hurting skiers, though, is to get really attached to a particular ski. Ski ends up in crappy condition, and the skier cannot replace it, as it is the only one that works for him and the model is not available anymore. In my view, it is better to change sticks every year than to fall into that. In my view, not patronizing here.
On physical conditioning, one thing is to be in great shape and a different one is to be in great skiing shape. The latest trend on this is functional movement training and lower body weight and muscular mass. Our top Open skier is doing that, and he is doing well. He is much leaner and less bulkier than one year ago. He has not touched a weight machine in a while, and does lots of balance and agility/coordination exercises.
He has been running 39 in training, and previously he struggled to run all his 38. He broke his PB in tricks with 10,180. If he manages to trick that, jump near his PB (68 m) and go beyond 5 @ 39 (his current PB), he will break the overall world record.