...A couple years ago, I picked up a really clean used Miller Vintage. I'd been looking for a 200 - 250A MIG machine for awhile. I have an old MM150 but its just not the best for anything over 3/16".
The Vintage is a 250A class machine and was Miller's remake of the infamous MM200. The vintage is an old school design with switches and dials, no electronic display, etc. It has 12 voltage taps, 6 on high and 6 on low, and as well, high and low wire speed settings each with 0 to 100 control. Makes for a lot of adjustments and it can get confusing but I'm getting used to it now and find I generally use just several settings since I'm mostly working with 1/8, 3/16, or 1/4 thick material.
I really like the arc it produces especially on the taps 1 to 5. It gets just a little harsh on the top tap (#6) compared to 1-5 but is still a very smooth arc. The welding on the 45 frame, which is close to 3/16" thick was done with the welder on low range, tap 5, using .030 solid wire with a shielding gas Airgas calls "Gold". I think its roughly a 75/25 mix.
Probably more info than you wanted.