You will for sure love the Harmony, set they are wonderful. I really like the Zephyr Acrylic needles a whole lot. The fact that some yarns don't slide as easily as on the wonderful wooden Harmony needles has for sure worked to my advantage too.
With both sets of interchangeable tips I really appreciate the fact that I am able to put on a round disk and use as a straight needle as well.
After my first purchase from KnitPicks site I have always been comfortable knowing that the quality as well as prices are terrific. I never question whether a product will be anything but excellent just like the customer service.
After further investigation, I've decided that I don't want to get the NPs. So I've firmly resolved that I will use both the Zephyrs and Harmonies, even if they do have a grippy feel with the yarn because I'd rather have safety than speed. I with metal (even with my Boyes) I have the worst luck at dropping stitches and it's got on my reserved nerve.
So, bye-bye metals.
Well, got my needles! I am very happy guy!
Will post pictures later.