Actuators, and corresponding methods and systems for controlling such actuators, provide independent valve control with a large initial or opening force. In an exemplary embodiment, an actuator includes a driver further including a housing defining a longitudinal axis and first and second directions, an actuation mechanism capable of generating actuation force at least in the first direction, anda rod with one end operably connected with at least one part of the actuation mechanism and with the other end available for an operable connection with a load such as an engine valve; at least one return spring operably connected with the rod through a spring retainer assembly and biasing the rod in the second direction; and a pneumatic booster further including a pneumatic cylinder, a pneumaticpiston operably connected with the rod through the spring retainer assembly and biasing the rod in the first direction, a charge mechanism providing a controlled fluid communication between the pneumatic cylinder and a high-pressure gas source, and a bleed mechanism providing a controlled fluid communication between the pneumatic cylinder to a low-pressure gas sink.