i have a big red machine .have used blue . i got my best bang for the buck with lincon machine . on my machine i could and did add the pluse controle panle on it at a latter date .i feel it a wast of money but looks cool more knobs. i have had 3 tig over the years all will work . my old round wave machine welded just as good as the square wave machine there some small things about the lincoln when welding alum but nothing to be gained on steel welding .but not any thing that could not be over come by cleaning the base metal better if you welding junk metal china stuff . no machine is going to make you shine. i like thumb wheel on the torch head as i use my welder off the table and over head if you are only welding on a table . many like the foot pedal