Couple things I read about those welders to make them better, a better ground clamp, like swamp said, and a better grade of wire, according to forums on them....that's all I got!, lol

You get better penetration with flux core versus gas shielded but you don't have a large enough duty cycle on these small welders for bigger jobs

This welder rides in my camp trailer full time when working in woods. My only complaint is a suitcase generator is underpowered, but a 3500 will run the welder. I had a job with a burnt up 30,000 lb generator we needed to snake off the mountain. I took half a day with this welder and a grinder and welded a d ring on the heel rack off a 330 log loader. We pulled the finals and worked the machine down the mountain. Half way down, the excavator cut free and rolled off the edge of the slope on the road. We set lift chains on either side of the undercarriage and lifted the excavator completely off the ground and set it back in the roadway with the harbor freight welded D ring. I won’t work in the woods without one around.

When we are guiding or doing depredation work, we spend several weeks or more on the hill with not much access to service trucks or even a Walmart to scab something together. I bring several sticks of rebar, some angle, half a sheet of expanded metal and the titanium and pretty much can have any vehicle back on the road in an afternoon.

Hats off to harbor freight. And yes Purchase the extended warranty