FWIW, I wouldn't recommend the HF 120V. Although it does weld, mine tends to trip the 20-amp breaker in 5 or 6 welds and it's the only draw on it. Lol, kinda' slows things down a bit.
Were you running it of a small wire or long extension cord? It pulls about 14 amps so that is going to create a bit of a voltage drop through a common 16ga cord. If so, I'd run it on a 12ga cord to eliminate the voltage drop.
I guess if I have a choice I'd definitely go with the 220V for $10 more. They weigh the same and I have 220 all over the garage. I'd love to find a used Miller but every time i see them, they are more $$ than I can justify.