La Marzocco's GS3 Espresso Machine is designed for the passionate espresso enthusiast who knows the only way to be satisfied is to invest in one of the best machines available. The GS3 is pricey, but its commercial-grade features more than balance the cost: Dual stainless steel boilers, powerful steaming functionality, PID temperature control, volumetric pump and variable hot water temperature regulation to name a few.