SpaceX boosters return by landing nicely thanks to an elaborate guiding system. This requires, well, a guiding system (so, more electronics, more opportunities for failure and massive engineering headaches), and also additional fuel.
The Space Shuttle boosters were also reusable, but simply parachuted at sea. This required a parachute, but no complex electronics and no additional fuel.
What is the benefit of SpaceX's method compared to that of the Space Shuttle, as it comes to reusable boosters?