Miller180 vs. Lincon 180
To start off with here is a comparison of both.
http://www.lincolnelectric.com/assets/en_US/Products/K2473-1/e7242.pdf of course this is off the Lincoln site so it may be slightly biased. I have been repairing welders for about 20 years now and can tell you they are both very good welders and both companies have great customer service. One thing to keep in ming is the Lincoln Promigs sold at the box stores are a decontented version of the Powermigs sold at the welding supply stores. Also keep in mind that the Hobart (Miller) and Century (Lincoln) are the big guys lower priced options. Both are well made but have had some things cut or substituted to lower the price they can sell them at. If you have a decent welding supply store near you ask if they have a machine you can test to determine if you like the way it works. Many will do just that for you. This way you can make your own decision on which one you personally like better.