The quality difference comes down to performance of the lens. Response time (light to dark) is a critical thing, I'd imagine.

I bought a Miller auto darkening pro helmet for about $180. I like it very much.

Doug

I think the tough part will be to convince the wife that it's worth the $$ to have your AC subpanel re-wired to either 220 or 30 amp 110. Otherwise you'll keep tripping the circuit breaker on your 25 amp circuits. If you do the re-wire on the house panel, be sure to get a heavy duty extension cord made out of super heavy cable. This alone will allow you to move your welder closer to your work. Being comfortable while welding is a key step to quality.

I plug my welder into the same circuit as my stove. She never cooks anyhow. As long as the phone works we can eat.

hahahaha "that's not a cooking timer, that's a smoke detector"

I purchased a Miller auto darkening helmet at Home Depot recently as I picked up a Hobart 140 mig welder. If I remember correctly it was about $150.00 for the helmet. It appears to be of good quality and I'm hoping the Miller name means I'm not burning my retinas. I am just doing fender flares on my 914 at the moment and the welder will probably sit a fair amount after that. Just to be safe I try to close my eyes for the split second it takes for the lens to convert once the arc is struck.

the difference in quality is how fast it changes over
, the plastic used for the head gear, the availabilty for replcament lenses, and how many sensors are in the helmet for change over. Again stating the obvious but I would rather use a standard jakson shadow then a harbor freight auto darkening. The flip down is so easy if you think about it logiaclly. You just have to have the knobs rather loose and stick your nose up in the air like a porsche snob:D It is true thats what I tell my students..

Personally, I noticed that the strength of the actual helmet was not as good on the HF unit. I am only a "home and very limited shop use" welder, so it wasn't that big of a deal when my first HF unit cracked. I chucked it and bought a slightly better HF unit. This is still working out economically for me with my limited usage. If I were welding a LOT, especially for a living, I would certainly buy a better helmet that would be more durable and last longer.

As for lenses, I'm going to provide a couple of good links for you. These should answer all your questions better than me trying to paraphrase.

http://www.hornell.com/hsi/faqautod.html
http://www.lincolnelectric.com/knowledge/articles/content/weldinglenses.asp

Good advice there. My welding instructor had a couple of helmets. The one he used for arc was a traditional. For MIG and TIG, he used a very nice auto unit. Fast and adjustable from No, 5 to 12, I think. No skull and cross bones, either. ;)

He nodded and flipped both; must be a habit for a long time welder. BTW, closing your eyelids does nothing. The bad rays go right through and burn. I got burned with my eyes closed and my head turned, just not turned enough.