Working with an experience bootfitter, I wound up in the right pair of boots based on my physiology, foot shape, ankle flex, etc. The right boots made a HUGE difference in my skiing.
Having those new boots then fitted properly and adjusted made a noticeable, but subtle, difference in my skiing.
Unfortunately, many sales people - and often our own self-assessment - base boot choice on comfort, fit and performance characteristics of the boot without regard to individual physiology and mechanics. Having a good bootfitter to assist in the boot selection is almost as important and the tweaks and tunes of the final fitting.
Merely my $0.02 ...