I have actually been researching this topic for a while. We have quite a few set ups at work, some with gas, some with flux. In the field a lot of times we contract welders in, and I always ask them their opinion for the best "over all" welder for home use...in terms of body work, motorcycle frames, etc., etc.. I am completely convinced from the professionals opinon and in my own experience that a "good" brand 110 volt mig with gas is the way to go. The Lincoln 135 mig with gas mix is what I am going to buy. With tools, you get what you pay for. Just my opinion, but I don't think you will be happy long term with the harbor freight. If you are just using it a few times a year to tack some things together that is one thing, but if you want a tool that will be around for years and years and you are really going to put some wire through it, I would get a Lincoln, Miller, or Hobart.
Hope that helps, and at the end of the day it is just my opinion...........