Gecko products are very good and reliable. As with any electronic device you must stay within their operating limits. The G540 can handle 3.5amps per channel and use a 50volt power supply.
One advantage the G540 has is that it has built-in electronic damping so the your motor resonance can be compensated. This allows smooth speed control.
Also, the G540 is a 10micro-stepper. This means that it takes 10 step pulses in to get one full step pulse out. If your motor were to take 200 step pulses for one shaft revolution then the G540 will need 2000 step pulses input to turn the motor shaft one revolution.