Just putting my 2 cents in. . .
I LOVE my Denise needles. I just finished making the hooded sweater from StitchnBitch using them, and the interchangeable needles made this so much easier. I could:
- switch needle sizes without taking the stitches off the cord
- use the cord as a stitch holder using the included "ends"
- switch from a longer cord to a shorter cord (or vice versa) by using the cord connectors and pulling the cord through until the stitches were on the cord I wanted
Etc, etc. My only constructive feedback is that the cord connectors which are supposed to allow you to connect two cords for a longer circular needle really aren't useful for that purpose. The connectors aren't flexible, so you end up having a 1.5-inch long stiff area in the middle of your cord, which is hard to work with. But I think it would be really rare that you need to use two cords together, so it's not that big of a problem.
Essentially, I think this is the greatest value for your money--you get most of the needle sizes you'll ever need, plus a lot more--for the price of 3 sets of circs. Who else can promise that?