"F**k! 30 kN lift for 1 kW power... what would it do with a 10 MW reactor??? If it's legit where is the kinetic energy coming from???"

According to the article:

"A prototype engine weighing 16kg produced 16mN of thrust with an 850W power supply, says Shawyer. With the help of private investors he is building a demonstrator intended to produce 280mN of thrust with a 1.1kW power input."

Then the 30 kN thrust is four orders of magnitude higher in efficiency than their prototype engines. If it were simply thrust they were increasing then you could just scale up the drive, but they are talking about over a 10,000 fold increasing in the efficiency of the engine. I'm rather skeptical of that.