The Vulcan line of welders from Harbor Freight do appear to be alot better quality than what they had before. Better torches, case, etc... As far as internals, there may or a may not be any difference. I can't say.
If you're planning on buying a welder and keeping it a lifetime, I would stick with a name brand, Miller, Lincoln, Hobart, etc... They've more than proven their worth over the years.
I have a Lincoln 180 that I couldn't be more pleased with. One thing that I've found is the quality of wire makes a big difference, especially with flux core. I ran out of the Lincoln brand wire so picked up some Forney at the hardware store. The Forney was terrible couldn't hardly hold an arc.
Anyhow, my $.02
