This cracks me up when I hear it. Your family car along with every piece of modern machinery including all the new tractors and heavy machinery coming out today are welded with guess what.... CNC MIG.
I don't know how much vicashoe knows about industrial welding, but if his entire exposure to MIG welding is confined to low penetration "short arc", then I wouldn't wonder at his not using MIG for a backhoe.
True enough, stick welding has been eclipsed by the various MIG processes in virtually every industry that utilizes heavy structural welding, leaving stick to do the job where greater portability is required.
Having said that though, a MIG welder that will equal an AC buzzbox, in terms of penetration and duty cycle, will cost many times what you'll pay for the buzzbox or for the small "suitcase size" MIGs.