I had a hard case for about 9 months and it started breaking apart on me around the 30-pin connector. So I ditched that and bought a silicon case. I was afraid it would be flimsy, tacky, or unstable to some extent. But I took it out and put it on the iPod and I really love it. It protects the iPod well, it's sturdy, and makes it feel really substantial in your hand, I was surprised. I like the look of it too. I don't know the shelf life of these, I guess we'll find out. I hope I won't have to replace it.
So to answer the question, protected, no doubt. Leaving it without a case makes it really easy to scratch. I don't like that at all.