I had to vote "Brand Loyalty" -- because I have never skied on anything but Kastle. I have no problem with that for two reasons:
1) Kastle's just 'work' -- and its hard to go wrong with one.
2) It's a lot easier to compare different models of skis of a single brand rather than broadening out to compare (and understand) between brands
3) I like the brand. It just feels right to me.
I would love to buy based on personal experience from a demo. But, in my region, as far as I can tell, there are no demos. At least none that I have seen or heard of...
Unfortunately, I am hesitant to take shop advice for several reasons:
1) Most shop personnel around me may be good skiers -- but they are not trained technicians. Essentially, when they sell they selling what is on their shelves rather than what is best for me. In fact, when I take my Kastle's in for work, most do not seem to have ever even heard of the brand,
2) There is just too much personal opinion involved in recommending a particular ski. This became especially apparent when I asked my local shop about tuning my skis and what would be best. The answer I got was: "Here is how we tune skis. If you don't want that tune (including detuned fore & aft), then go elsewhere. They seem to think we are to just do what the doctor tells us without question.
3) Until somebody has seen me ski I have trouble believing that they understand my needs. A 60 second description of my skiing style and abilities just doesn't cut it -- especially since I am 65 and the clerk has already made up his mind how I ski before I even open my mouth...
So, I stick to my own advice -- and when buying Kastles, I figure I can't go too far wrong.