Weight to mass flow rate:
A reciprocating air craft ic engine power engine
Developing 300 KW handles 2 kgs/sec of air weighs
Around 9500 N. Whereas, a rotary gas turbine of an air
Craft for same 300 KW power can handle 22 kgs/sec of
Air and weighs only 8000 N handling more mass of 
air/sec. in stationary power plants, the specific weight of
reciprocating power plants will be 10-15 time higher than
the turbo power plants