Actually ball valves aren't great for throttling, unless you're talking about something like Fisher's vee-ball line. With that exception in mind, usually you'll only want to use them for block valves, like gates & butterflies. The advantage they have over gates (depending on size) is the quarter-turn operation makes them easy to fit with relatively low torque actuators. For throttling you'll usually want to use a globe valve. For instance, in the natural gas field, emergency shutdown valves are usually quarter-turn ball valves rigged with pneumatic piston actuators. Manual block valves at battery limits and such are usually gate valves.