The tube is fine. I dont like the clamps or flanging. The clamps are two wide of a gap for me and the flanging prevents you from being able to planish, makes bodywork harder, and leaves a place for moisture to accumulate.
I will use the clamps if my gap is bad and allows for it but I prefer a gap that is no wider than the wire thickness I am using. Here is what I shoot for. I tig most of my sheet metal work now but keep the fit up the same.
When using mig I will set the welder to somewhere between 1/8'' and 3/16''. I never do two tacks next to each other. This is done with mig. This was three rounds of tacks letting it cool in between. I would normally planish in between each set of tacks but I didnt have anyone to hold the dolly with this section.
Now for fit up I use clecos. They are really cheap and easier to work with.