We did a lot of DualShield when I worked at the Veco shop in Anchorage. We were using Lincoln wirefeeders, LN25 I believe it was. It took me a long time to get the hang of it, but I finally got pretty good at it.
For the cap on a position weld, I found around 27.5 volts was about right. I would set the wire speed around the same as the volts: 27.5 volts, 275 wire speed or even 10 or 20 less at times. You have a different wirespeed set up. You want to go by the sound, set the wirespeed so the puddle is making a 'ssshhhhhhhh' sound, if it's crackling the wire is too high. Mind you, this is just for position welds. On the rollout welds on the positioner I set the volts on 32 and the wire on 550. Smokin' hot, but slicker'n a minner's d!@k. Pretty tough on the welding shirts, though.
For your weave motion, you want to go back and forth pretty fast to keep the whole puddle fluid. If you go slow, it's gonna look like crap. You can't really use the same weave as a 7018, it doesn't come out good. You want to go side to side real fast, and don't go up in a big step like with 7018, you want to take baby steps.
That said, you really can't make DualShield come out as pretty as stick, it just don't work that way. They use DualShield cause it's fast, not cause it's pretty. And always remember; ugly shoots, too!