My table was set up by my dealer before I bought it, and he did the single twist.
Today I couldn't leave well enough alone and went double twist. I'm not sure it's a feasible way to go. With single twist, when I rotate the ring to adjust azimuth, the arm moves nice and smoothly back and forth. With double twist, the junction where the strings overlap moves with the ring. IOW, since there's a double twist the strings can't pass each other easily, so the arm moves hard to one side and then jerks as the strings release. And once I moved the ring/azimuth, I couldn't really get it back straight again.
Needless to say I'm back to single twist.