Most of the Davies are engine powered. Also, the MC-1 are rated about 3500 psi. However, the MC-2 can deliver higher pressure. This might be important if the compressor is being purchased to fill high pressure banked air. On the plus side, there are manuals available and a number of people who potentially could help troubleshooting typical problems of a surplus Davey. A good, used unit could be a significant bargain. Alternately, there is a plethora of used, high capacity compressors selling on EBay every week. They come from industry, fire depts, govt, etc and the big compressors often sell low because the larger share of the (flea) market is for small machines. If the intention is to purchase an electric motor driven unit rated more than 7 cfm three phase power is often required. This rules out most home users.