But I did notice a video by ChuckE2009, where he demo-ed one, and had an obviously bad time with AC arc starts on aluminum, if I recall correctly.
Chuckee is the same guy who dismantled his harbor freight portaband to change the blade....completely idiotic. I am sure his issue with arc starts could have been alleviated by checking the ground and/or using a non contaminated tungsten. I wouldn't put too much faith into anything Chuckee says about anything Harbor Freight. His paying sponsors wouldn't be happy if he said a Harbor Freight welder was just as good as anything in it's price class. I am sure he is biased since he doesn't want to bite the green/yellow hand that feeds him.
That being said, Harbor Freight really will stand behind their try it for 1 year money back guarantee. I bought an Omnipro 220 that wouldn't stick weld at all...defective unit. I brought it back and they not only refunded the purchase price, but the extended warranty as well, no questions asked. I loved the way that unit MIG welded. So don't be afraid to buy one and try it. You really have no risk which is something hardly anyone else offers you.
Terry (Shovelon) said he ran a beta model of the Pro-TIG in production until he smoked the torch, and said the unit did pretty well. Hopefully he will be along here shortly to give you his own words. The only real gripes people have had is the machine doesn't have an adjustable post flow timer, and they squawk about the cost of the wasted argon shielding gas. To me that dog doesn't hunt. If the machine has a post flow that is 15 seconds too long, then 15 seconds of argon at 20 CFH per hour is 0.08 cubic feet of argon, which cost between 2 and 4 cents depending on where you get your gas and the size of the bottle you buy. You lose more money in the cushion of your couch than you will lose in argon costs.