autoset is great for just turning it on and letting the computer do the work. all works off voltage readings, IIRC the miller does something like 1-5000 checks/sec. a bit on the low end, but still works great. that autoset is nice, and if you ONLY have 110v, it's a great machine. i'm actually looking to get one of these:
http://www.airgas.com/browse/productDetail.aspx?Category=231&product=MIL907422
-autoset, dual voltage, spool gun control, yada yada. the miller lab is 2 miles from my place and a buddy is a rep there, so i can play whenever i want! i can also get that 211 for $700 brand new.
re: tap controls - great for a novice or hobbyist welder. you just look up your plate size combo and set the wire feed speed and voltage "number" and go. i have more experience welding and would like an infinite (rheostat) control where i can precisely fine tune my wfs (amperage) and voltage when not using autoset.
basically, buy the MOST welder you can afford. have a MINIMUM budget of $500, anything less than that for a new welder will get you crap. don't be scared by a 10% duty cycle, you have to pay to play for higher duties. additionally, most 110v welders max out at 20%, there's just not enough current to keep em going! those transformers heat up QUICK!
also remember if you're going to want to have nearly zero cleanup post weld, you'll be welding GMAW and you'll need a bottle of 75/25 mix shielding gas. otherwise, use FCAW (hobart comes with inner-shield/self shielded wire) and don't worry as much about joint prep. just remember, you'll need a wire wheel to clean up the slag afterwards.
also, remember, if you're welding vertically (the joint is in a vertical plane) then weld downhill with GMAW (hardwire) and uphill with FCAW. if you need details i'll be happy to elaborate on this.
