The fuel burn of the EC120 is between 32-38 US Gallons an hour cruising either 110 or 120. When light the fuel burn is even less. I don't consider that high.
The cruise speed of SW4 is lower anyway so I don't think the fuel burn differs a lot. But I don't think you should compare the SW4 with an EC120 anyway, I don't really know where it fits in anyway, I think the design is pretty old fashioned (the interior looks .....) and the only advantage over a Jetranger would be the three blades.