I have been wanting to try a veggie spiral slicer for awhile now, as I've seen it all over these blogs, as well as constantly popping up when I search "low carb" on Pinterest. I bought the GEFU spirelli spiral cutter off amazon for about $30. I've only used it once and I'm already in love!
There are basically two reasons to use a spiral slicer. 1) to make fancy veggies for your salad and 2) to make veggie "noodles".
I used it for noodles last night. Sakief and I had spaghetti with zucchini noodles for dinner. It couldn't be more simple to make the noodles either. I read a few reviews saying that the slicer was difficult to use, but they clearly don't know what they're doing. All you do is pop whatever veggie you want onto the twist cap, insert into either end of the slicer (two settings, thin and less thin, haha), and twist the cap. It took me less than 10 mins to slice 3 zucchini, and it only took that long because I was playing.
To make the zucchini a better consistency for noodles, I steamed them. They were pretty al dente, but zucchini isn't an overwhelming flavor, and they were twirlable! I think Sakief and I both agree that zucchini noodles are better with spaghetti than spaghetti squash (but I still LOVE my spaghetti squash).