I have one and over the years it not been that good, but I fitted a new wire welding wire linner of the metal kind as opposed to the pvc type, (less friction on the wire) and it seems to have transformed the SIP 130, read more on the link about wire linners, at the same time I improved the heavy wire were it starts its way up the tube to the torch,
Just welded 2 new dumb irons on with mine and am very happy with the quality of the welds
http://www.mig-welding.co.uk/
Nick.