The act of skiing puts a lot of unnatural forces on your feet and legs. This is due to the fact that there is a need to restrict certain movements to transfer your bodies energy through your skis. These forces demand that you be secured in a hard plastic boot. Where the comfort aspect fails for many people is that the boot they are wearing does not surround and support the foot correctly.
True comfort is achieved when your foot is stabilized, relaxed and you have good blood flow. You want your boot to be an extension of your body rather than just being on your feet.
Being warm and comfortable is an experience worth having and it all begins with a good foundation.