I like this topic, but I believe the original question should be: When Is The Best Ski The Wrong One For Particular Type Of Skiing?
Skiing is a very broad term that spans all types of activities from: racing (that in itself has different types of skiing and skis used for it), park free style, big mountain free style, powder skiing, moguls, trees, West Coast, East Coast, carving, shifting, switch, jumping, you name it. Each of these activities requires the ski to be different, or different setup on the same ski. No matter how much advertising companies put out, every ski out there adheres to laws of physics. A given pair of skis that is good in one activity is going to be weak in another type of skiing that demands something else from the ski. That is the truth and there is no way around it.
As you can see skis can be very sensitive. They matter more than tires on your vehicle. You get your tires wrong, you'll feel a small difference, but you'll be able to drive. You're going to get your skis wrong, chances are you're going to hate skiing all together.
I am 100% convinced most people buy skis blindly, reading online opinions on what is "hot" (Mantras and etc). Those hot skis are probably very good, but they will not fit everyone. One must understand their own skiing ability, and their new ski purpose in order to even start looking for a pair of skis. That is how I bought all of my 6 pairs of skis. Each pair had a unique purpose. I knew what I wanted from the ski. On top of that I knew the length, and setup characteristics of the new sticks I needed. At the end I ended up with a specific pair of skis for my ski activity, and I love all of them as they are doing what
I wanted them to do.
If it's going to help anyone I'm going to post how I find good skis:
1. I figure out what I need the ski for and what the ski has to be good at. Here if I don't know I ask on the forum for ski characteristics.
2. I figure out what I can handle and what the setup should be (length, bindings, setup)
3. I go to Free Skier . com Every year they have technical reviews for skis in many categories. They do not run a popular contest, but rather technical reviews and they provide what the ski is good and bad at. Then they score the skis. The score has never failed me so far. Never, and I mean never go by popular skis. Most people I see at ski resorts are on wrong (not optimal) skis.
Having said everything, I must admit there are surprises. My latest bump ski (Blizzard Bushwacker 2013) shocked me. 88 waist, up to my forehead 168cm (short by my standards) ski handles way better (except ice) than a pair of super expensive racing (almost) skis I have by Kastle. Not that the ski is "better" as those are two different skis, but one that is suppose to handle well does not comparing to another less handling ski if you will.
I'm not a good skier or anything like that, but I do it all, so I sort of have a feel for the skis by now, and I use good equipment to help me hide my lack of skills :) Hope it helps.