I just measured the quiescent power consumption of the board, without any load, and it gobbles up 48 mA just sitting there, powered from a 5V smooth supply. This, I figure, would be power loss that would be in addition to the 10 percent total power loss reported as "%90 effeciency", which would be an additional tax on each amp that crosses the board of 100mA. So if your demand is 1 amp, it will probably ask for around 150 mA to operate, which is considerable in some applications. The board has operated very smoothly, and is incredibly cheap. But, for battery powered applications, or solar-powered applications, it is a hard decision to make whether to include it or not. It has worked perfectly to drive NPN MOSFET gates on the high side of a 12V DC motor H-Bridge (all NPN MOSFETs), which makes for cheap and effecient high-side switches, compared with PNP MOSFET, which have higher on-resistances. I think the lower on-resistance of a well-saturated NPN MOSFET gate is well worth the 48mA power-tax of this boost, especially if you're driving dozens of MOSFETS for high-current-draw, from that smooth 18V from this boost. But, for example, if you're just driving one single motor, this board's 48mA might be more than the power savings achieved by low RDS-on. Still, this is a solid board, and DFRobot's buck, also sold here, is amazing.