Tire & Wheel Packages add convenience to the seasonal changeover. All that is needed to make the swap is a jack and a lug wrench. While the changeover can be accomplished readily with only hand tools, power tools can make the process much easier and more enjoyable.
Aside from a high quality floor jack to use in place of the jack in your trunk, the most important upgrade is an impact wrench. Using a good cordless impact wrench can cut the time needed to change out a set of wheels and tires in half. With power to break sticky lug nuts loose without having to use a breaker bar, the impact wrench reduces the muscle needed to get the job done. It also eliminates the time spent switching between the breaker bar and a regular wrench.
One thing an impact wrench should not be used for is torquing down the lugs. A torque wrench set to the torque specification indicated by the vehicle manufacturer should always be used to ensure proper tightening.
Having used both hand tools and an impact wrench in making tire changes, I can testify that it does make a substantial difference in the speed and convenience of a wheel changeover.
For more information on torquing, read "Wheel Lug Torquing."