I am not a professional welder but I had repetitive problems with wires getting stuck (in the tip) and the problem was that I was using cheap wire. Don't remember what brand of wire. I also had poor weld quality (unstable arc, weird looking joint) with another brand with a spool that was given to me. Since I hate wasting resources and I don't have much time to waste, I only buy Lincoln Electric wires. May or may not be the best but their quality is constant and I never had any troubles with those wires yet.