Besides minor changes in core materials and builds/sidewalls etc, I think most ski technology has been thought out. Unless you count magne-traction and various other gimmicky things. That said choosing a brand is just deciding
1) Who builds a quality ski
2) What flex pattern/ride style you're looking for
3) What topsheed style you're looking for
These days not many people are building a truly low quality ski, so anything you choose comes down to those 3 personal preferences. I ride lines, surface, and libtechs not because I like the brand but because the lines are big and moderate flex for all mountain, the surfaces are still mountainable but better in the park, and the libs can carve shitty east-coast ice.
Screw core brands and alla that, just buy what works. Brand loyalty is stupid unless one brand delivers a model for all you riding styles.