Just received one today - 2.2ohm from Sweet-Vapes. Virtually identical to the single-coil attys, there's just another wick/coil slightly above and perpendicular to the original (with a slightly modified gasket to accommodate the second wick). Installed as easily as ever in my Vivi Nova STV. So far it's delivering a fantastic vape. There's the slightest bit more "gurgle" now, but it's still barely noticeable. The vape is full and cool at 3.7V, two things I've been looking for.
The only minor issue I'm seeing so far is that the wicks are just a bit too short. They don't quite reach the bottom of the tank, so earlier refilling will be necessary. I try not to bottom out my tanks anyway, so it shouldn't be a huge issue.
I'll update this as I continue using the atty.