The leverage principle has been key to providing many high-quality compound exercises (the major, multi-joint movements) on a single machine. Leverage permits the replication of natural angles of movement, provides balance and stability, and best of all, offers movable, steel-pin safety to prevent a load dropping in the wrong time and place. This lets serious lifters train without an extra person in a safeguard role.
Powertec designed the original leverage home gyms nearly 20 years ago. They've stood the test of time and have been frequently copied. All carry the highly-requiring European EU-957 standard for performance and safety, are tough and are of extremely high quality. Few others imported to NZ (if any), carry the EU-957 certification.
Leverage gyms offer several very major benefits over others. They provide the most important and productive exercises in a highly effective form. The major proportion of so-called "home gyms" don't; in fact they do little that's useful. They're often cheap-to-make devices with a few vertical cables strung through pulleys to offer mainly isolation (single muscle) exercises. They provide very few of the important, heavily-engaging pressing and lifting movements. They also provide minimal adjustability for body size, and grip variety - very important for proper development, and exercise variety. The structure is typically flimsy, which reduces pleasure and commitment.
In short, well-designed leverage equipment provides the power of free-weight training (for instance, rack, bench, barbell, weights) with the control and safety of a machine, with excellent space-efficiency.