I was referring to the use for GTO-GSO orbit raising, where it's less mass efficient than both hydrazine and ion engine propulsion. But the Isp might be so low

I was referring to the use for GTO-GSO orbit raising, where it's less mass efficient than both hydrazine and ion engine propulsion. But the Isp might be so low only because of scaling issues on a device that has to fit in a microsatellite. If they do meet their target of 900 second specific impulse on the larger models, then it might indeed be very useful.