I weld pretty much all day every day, we run 2 lincoln 355's, 6 lincoln 255xp's, and we have 3 different millers (not 100% sure on the model numbers on the millers, but theyre all 3 220v) at work. 2 of the millers have Tweco leads on them, and 1 has just the standard setup.
I'm not a fan of the millers at all, we do a lot of industrial grade shit (3/8, 1/2, 5/8 materials) and the millers will not 1 pass any of it without overloading the machine. Miller's feed in kind of a weird manner too IMO, and they're a little harder to control your bead with than a lincoln (just my opinion there). The lincoln 355's are a bitch to get used to, but once you get them dialed in they're great welders, and will do anything you need them to do. My favorite though, is the Lincoln 255 (which i believe was replaced by the 256 this year, same thing, just newer and more fancy) for how smooth it runs, and how hard you can work it with no issue. IMO the 255's are reasonably priced a well if you do some looking around.
Industrial type welders are very different. And, IMO Lincolns do just fine once you get to the 255 and up welders. Mainly because they aren't outsourcing those unit to be made in mexico. The 255 is the first unit that comes with a legit gun. Its a good welder. My issue is with the smaller, entry level welders.
My experience with the Lincoln's having owned a 175HD (Home Depot version) and a Lincoln 180(non-home depot model) is that both fed line like pure crap. The guns, liner, tips, nozzles, etc were very poor quality right from the get-go. I was so fed up with the 175HD that when a customer asked me if I had a welder for sale I let it go with a custom cart and bottle for $500 on the spot. The 180, I only used for a few weeks. Still wasn't all that impressed with it though. And, it had the same useless gun. I really like having infinite power settings too as opposed 4-5 settings like most of the Lincoln's have. Miller has infinite power dials. Hobart doesn't.
In comparison, Miller's entry level machines are still made in the USA, and their warranty has been awesome. I have gone through one mother board on my 211 Autoset in 4 years. Hardly the welder's fault since I literally use it to weld just about every bumper we sell. It welds all day, everyday as well. So, we are using it for a lot more than its designed to do and just keeps on going. I drop it off at Airgas in Boulder and Miller handles the warranty claim in a few days. Its that simple.
Good luck getting Lincoln to handle a warranty fast on a Home Depot model. I have read horror stories on a lot of the fab boards I am on.