The Blog Forum is only for blog threads. I've moved this post to General Knitting since this is just a general question. If you want to start and actual blog thread please feel free to do so though.
If you do a search for "interchangeable needles" you'll see bunches of threads. I'd guess the vast majority of people find interchangeable needles not only a worthy investment, but nearly indispensable. I have the equivalent of at least 2 or 3 sets myself.
I suggest if you are considering them to not just buy any set though. They vary in price and quality, etc. So I suggest trying as many different kinds as you can. I don't recommend the type you tried, but for a different reason. The plastic cables tend to be stiff and don't lend themselves to some types of knitting. There are cables that are soft and flexible which are a vast improvement. You don't need to spend a ton of money though. My needles are Knitpicks Options nickel plated because I prefer metal. Knitpicks also has 2 different wood options as well as a plastic needle option, but all have a soft flexible cable.
I suggest trying the Try-it set and see what you think of the different types.
While you're on the site you can check out the prices. This brand is by no means the only ones out there, but they have excellent customer service if you have any problems.