So are you looking at the ones that are about $55.00? I ask so that people who give an opinion have that number in front of them since it's an important issue for you.
First of all, I've not bought the Denise needles--mainly because many people here do not like how inflexible the cords are. They're too thick to do magic loop or traveling loop.
Have you also looked at the interchangeable needles at Knitpicks and Webs? They are slightly pricier, but the cords are very flexible and can handle magic loop well.
I recently bought a set of the Knitter's Pride Dreamz Interchangeables from Webs. I love them! That was money well spent.
Also, Boye recently came out with a new set of wood interchangeable needles (and nickle-plated, too, I believe). It looks like the cords for these new sets are comparable to the cords of the Webs and Knitpicks needles, but I have not tried them, and I've not found a lot of reviews on them. So I leave it up to you whether you want to take a chance on these or not. Historically, of course, Boye has made lots of high quality products, but that may have changed in recent years.
There are other brands--Hiya Hiya and others, but they are much more expensive than the Denise needles.
If you're determined to go with the Denise needles, I saw that someone on here has a set for sale. Will try to figure out who that was. Also, I notice at the top of my screen there's an ad for Rainbow Denise Interchangeable Needles available from Knitting Help--it also says "Free Delivery."
ETA: Okay, I found the poster who had Denise needles for sale. Her user name is artsy1. You can search for her post, click on her user name, and then send her a private message.
You're sure to get lots more feedback, but you can also search KH for "interchangeable needles." It's a topic that's discussed with gusto about once a month around here.