Edit. I thought that I'd posted this in the questions but ended up in General. So I thought I'd tag Matt Hayden in case he doesn't see it here. 

Not real crazy about what I saw when cut and etched some sample 2F welds with the dual shield at 25V/250 IPM 35 CFH C25. They look OK on the surface, but about zero root fusion, and pretty shallow penetration. The etch wasn't great and didn't photo well. The 1/4" material was spotless clean and square; no rounded over sheared rolled edges. It was belt sanded square. Maybe I was traveling a little too fast? The throat is definitely under 1/4". Thoughts anyone?

Photo 1 cross section is pull beads top left/bottom right, and pull top right/bottom left. Photo 2 is pull, and Photo 3 is push.

Edit to add: Not sure what the hell is going on. Ran two more beads. Photo 4 is 25/250 and photo 5 is the Auto Set suggested 22.9/265. Slower travel speed to build up a bigger bead, which it did, but as you can see in the last photo, the root fusion in both is terrible. Squashed it in the 40T press and it held up OK, but I would hope so, welded on both sides.

Question for you guys that run a lot of dual shield. Do you think that "slag you drag" is a hard rule? I was padding beads of .045" Lincoln 71M Outershield( C25 gas ) at on plate today set to 25V/250 IPM. Dragged the beads left to right, and pushed the beads right to left. Darned if I could tell the difference. Just used a very slight ( 5-10 deg ) tilt either to or away from the direction of travel, with the gun pointed straight in. I haven't tried a cut & etch yet to see if there's any difference inside, but on the surface it runs great either way. Love the spatter free welds. I must admit I was wearing Crocs and never so much as felt a spark in an hours welding! I know, I know, it's not proper footwear. My shop, my feet, my rules! :)

My neighbor brought me a couple of receiver hitches that came off the fleet of snow machines that are used to groom the Iditarod trail before the sled dog race is run each spring. These machines take a pretty good beating, and the hitches have a couple of common failure points. He wanted me to see if I could add a few additional beads to beef them up. After burning off the powder coating and bead blasting, they were good and clean. Added a fillet around the three un-welded faces of the tubing, starting and ending on the ends of the lone factory weld. Then butt welded the inside end of the tube to the flange. He was very happy, and will be bringing in six brand new ones to receive the same mod, before they install them on the fleet. I chose ER312 filler, as I wasn't sure if it would be 100% clean, and it's supposed to leave a ductile, crack resistant weld. Plus, I just like the way it welds! Turns out the weed burner/bead blast got it plenty clean, so I'm sure plain old ER70S-2 or -6 should be fine for next ones.