Same here. It is impossible to do magic loop knitting with these. The "cords" are too think and stiff. I think that is why I had to tug on them so much to get the knitting up and around the needles.
I bought a set of 15 bamboo circs on amazon.com for only $24. I work them a lot and I LOVE them. And some of them aren't sharp enough but I used a nail file to sharpen the tips of them.
Anyway, my denise ones are now collecting dust as the only method I use in the round is magic loop.
Dont feel too guilty, if you knit a lot it pays to have tools that work for you and that you enjoy!!