This comment does a pretty good job of covering the important things. My work has an AC TIG so I'm covered for aluminium welding if I need it. I think the onl

This comment does a pretty good job of covering the important things. My work has an AC TIG so I'm covered for aluminium welding if I need it. I think the only other thing I've noticed about the cheap DC TIG I've got is the build quality is, well, cheap, but if you handle it with a bit of care they seem durable enough. I've accidentally dropped one of the name-brand ones from 6' up a ladder and it just bounded and kept going. Not convinced I'd want to do that with my ~$200 unit. Probably a good idea to let the unit run for a good 5 minutes after you've finished welding to make sure it has a chance to cool down. I had a MOSFET blow out on the first one I bought, I think because I was switching it off immediately after doing quite a bit of welding and the fan didn't have a chance to blow away the heat build up. But even after buying two of them I'm still a good ~$1000 in front of a high end unit.