Basically to compare them, just look at items like max. amperage available and the duty cycle at that amperage. The lincoln may be 255 amp at 35% duty cycle, but the sears could be 260 amp at 15% duty cycle which = bad. These are numbers I just pulled off the top of my head so I'm not sure what the actual numbers are, but you get the idea. I like my lincoln 255 alot though.