I have a Miller auto dark and just got a new job TIG welding and Mig welding. Mostly stainless steel. The problem is that the welds are on 3/4 to 1 in material and the darkest setting is still about 1 shade not enough. After the 2nd day my eyes are really tired. It's hard switching from one process to the other but the auto dark is easy to adjust. It's just the MIG on the thick stuff is really bright. I even tried adding sunglasses but if anything they made it worse.
I used a whole spool of .045 wire in 4-5 hours. It's almost non stop. Then switch to tig. I'd guess at least 5 pounds of rod. They told me there is an even bigger job coming.