There is no one best ski length for a person. There is only a 'better' length for a particular ski for a person and that length is truly dependant on all the factors in the beginning of this thread. That is why many of us have quivers. For example:
For really short, powerful turns on hard snow, I use my P60 SL slalom skis at 155cm.
For versatile all around skiing and hard bumps on hard to medium snow, I use my 6*, now in a 168cm, up from my original 161cm after being able to demo both on the same day.
For really soft snow, crud, slush, and pow, I use my Karmas at 177cm for power in the crud and stability in the longer turns and higher speeds used to negotiate that stuff.
For medium to hard snow at the highest speeds and biggest turns, I use my Ractiger GS at 180cm.
Obviously, my height and weight don't change with each ski, so each length is chosen based on the skis' designated speeds, turn sizes, and snow conditions. All will function in each condition, but each has their niche for optimum performance. QUOTE]
You've summed up the dilemma for those of us who can only afford one ski. I'm hoping my Fischer Visions 70s will do it all! That goal may be attainable given my intermediate level.
I'm curious---do you sometimes take 2 or more skis with you, for changing conditions?