I have options and bought the harmony set for when I don't want something so slick and because they're, well, just plain purty.

I also have a set of Denise needles (they were my first foray into interchangeable's) which is the only reason I haven't bought the zephyr's. I'd still like to get the zephyr's though because the cord on Denise needles is fairly thick and I've had issues with them coming apart.
So, it's really totally a matter of affording the expense of the needles if you ask me :P I'll buy the zephyr's myself someday even though I don't necessarily need them because the cords are the right thickness for me, I love the company that makes them, and I may have a needle addiction.
