I love them, as a texture substitute for noodles or pasta (spaghetti, fettuccine) in a good sauce. They have no taste on their own, unlike, for example, courgetti (courgette ribbons) or spinach, which I also use as a pasta substitute.
I tend to stock up at Holland & Barrett's penny sale, which comes up every few months or so. Slim Pasta/Noodles/etc. are usually £2.99 per pack (large serving or two small portions).