addi FlexiFlip Needle Demonstration

I am a sock knitting addict and first heard about the addi FlexiFlip needles at my local yarn shop about six months ago. I have been chomping at the bit to try them ever since. The needles come in sets of three and are similar to DPN's, but have a short, flexible cord at the center. These needles are especially designed for small projects, like socks, that are worked in the round. But how do they compare to to knitting socks on dpns, magic loop or two circular needles?