The problem with the 172 is it does not like to weld with .023 wire very well.The miller130xp is what you want if you have to have a miller.The mm 185 suffered with poor .023 welding also,but welded great with .030.I just don't like the new miller.I have owned two 130 millers,one was the xp.The lincoln sp135 plus,and the lincoln sp175 plus is the best little welders out there.My sp175 welds way lower than about anything out there,so does the sp135.Great arcs,as good as my mk pulse welder.In fact I would have to play with my inductance,and slope to get the inverter to weld as nice.I don't know how they do it but they have been playing with that machine longer than anybody else.The 172 only goes downs to 40 amps where the lincolns goes to 25 amps. I would still pick the 172 over the 135 in a heartbeat,and just try to mess with the gases to help with the low end maybe some 85/15,then some 90/10.I do like copper transformers in the miller welders.My 1.5 cents.At one time I seen the 172 new for about $600.I just traded my mint 130 xp in to the welding shop for 400.00 they sold it for 430.00 So somewere around that price.The guy that bought called when I went in to the shop.He called to say he was real happy.