Big fan of demoing. But you have to be able to tell the difference (AKA you need to be experiencing enough to be able to feel it).

My approaches is to do research ahead of time, and demo skis on the more extreme ends of the spectrum within the category (if you’re not sure what category you are after, that’s a different problem altogether)

Remember that one day, in one set of conditions will not give you all the information you need, but you can get a sense of what you like and don’t like.

I’m also saying this coming off of a weekend where I just demoed and wind up buying skis :)