Know this: If you're still skiing in old rear-entries, or in boots that hurt, or in boots that are just too big, your super-sidecuts aren't working at peak efficiency. In the past few years, manufacturers have quietly wrought significant evolutions in ski boot design, without the fanfare that attended the shaped-ski blitz. Fit and flex remain the twin towers of boot performance, but substantial improvements in manufacturing technique are making it easier than ever to fit differing foot shapes while improving power transmission. "Co-molding" and "bi-injection" (that's tech-talk for "using two plastics") enable manufacturers to use softer plastics in sensitive fit zones while using rigid materials in power-transmission zones. Multi-material boots are also dramatically easier to put on and take off, and retuned flex patterns¿softer forward, stiffer laterally¿better suit the demands of shaped skis. These are subtle but crucial features that older boots don't offer. And there are others. The new macro/micro-adjustable buckles fine-tune cuff fit, accommodating most calf shapes. So do adjustable and removable cuff spoilers. And more companies now offer a choice between high- and low-volume liners, with built-in shim pockets for additional customization. Even lower-end models are using sophisticated "memory" and heat-moldable foams. So if your boots aren't all you wish them to be, do yourself a favor: Head to a ski shop and pick up a pair of gold medal winners. You'll ski better. And your feet will thank you.