belt drive units ,oil type, are much quiter. twin v cylinders run smoother,produce less heat,more cfm,and less moisture. they are less maintenance free and the cost of repairs are much less on parts. oil free compressors run hotter, have more noise,and are short lived. you should consider a 2 cyl cast iron 60 gal single stage if using in single bay shop. if you need lots of air, 2 stage are excellent. kick in at 125 off at 175 produce aprox 19.o cfm per min. if need further look at www.tool-central.com