Some weeks I do more aluminum than steel. I'd throw out my coffer maker before getting rid of my spool gun (and if you knew me you'd know that's saying a lot ...lol)
I'm leaning towards the Lincoln 210. The miller is a nice machine, and while i don't really care for the whole walk you through the set up on a video screen approach of the Lincoln, I do want voltage and wire speed read outs. When I find the sweet spot, i want to know what it is. And the continuously variable voltage helps find it.
I often finish a task (say 1/8 alum angle), switch to another job (maybe steel), and later come back and do more work on the alum angle. I hate having to find the sweet spot again and trying to remember ... oh yea, it was voltage 4 and speed about half way between 6 and 7. The numbers dials are a pain in my book. Every machine should show me what it is doing. I want to know 18.4 volts at 330 ipm etc. So the Lincoln wins out on that point.
The simple readouts (like an everlast) would be fine, but just dials with numbered voltage is annoying. Have you ever wondered if voltage 5 on one machine is the same as voltage 5 on another? The simple LED number displays cost about $1 in bulk. Why they don't use them is a mystery to me.
I considered the hobarts. They have good reviews and are a little less, but since Lincoln raised it's price, so did they. Their 210 dual voltage is an 80lb transformer model with no readouts and only saves me about $200 but then the spool gun costs more. I think in time I'll forget what it costs, but I will always notice how much I like using it, so I'm going to bite the bullet and go Lincoln unless I find another of similar value. If Miller had a display I might have gotten theirs.
The everlast models were interesting. They have inverter models with extra features better priced than Hobart, OK reviews (a few quality issues) but they are out of stock and don't expect more for weeks and their spool gun will cost more than the Lincoln if i get the package from Lincoln.