Yeah, Magnezone is a strong Pokemon.
In a metagame where offensive threats have taken over, Magnezone finds it difficult to truly fit in. Despite its major offensive presence in its Special Attack, Magnezone is outsped by every single offensive Pokemon in the tier; most of them wielding a super effective attack against it. Walling Magnezone isn't that difficult either with Pokemon like Hippowdon and Celebi.
However, one must look closer to find the real usefulness in Magnezone. It has an excellent ability in Magnet Pull, an ability that traps Steel-types; as Magnezone has all the necessary tools to rid of them, specifically its STAB Electric-type moves and Hidden Power Fire, it's not only an aid to Dragon-types, it's also helpful to teams that struggle against Steel-types in general. Despite its common weaknesses, Magnezone's Steel typing grants it some useful resistances and is paired with its decent defenses. One must not overlook its stellar base 130 Special Attack as well. Overall, Magnezone must be used with caution if it plans to guide the team to victory. ~Smogon
But it depends on your team. If you already have Steel and Electric types in your team the answer is no, otherwise sure it will be good.