I have a 180, It is a excelent machine. I have never needed more power than it puts out yet. I don't use the tig for real heavy stuff, but for .120 wall tube it is sweet. I use the stick feature more than anything. It does aluminum nice, I have tiged up to 1/4" Al plate and it was fine. I have also done thin al and ss down to say 16GA and it works great.