I'm not sure if its the wire as I didn't really do anything with it in the old welder that required me to actually look at the welds afterwards, but it seems to pick up porosity quite easy, but then that could be me or the welder. It seems to be very 'twitchy' with regards to torch/travel angle and if the torch is slightly off (too much angle) it seems to flare up and if its too upright the spatter is crazy (yes ive got the polarity correct) but when I concentrate on torch angle it welds quite nicely. Only problem is im so used to being able to just do whatever I want with the transformer and still get decent results that having to concentrate on torch angle means I stop paying attention to where the puddle is