I did try an Icy Box so I could read the hard disks from my dead Mac on my PC. It was well-made, but unfortunately the drives didn't work in it (wrong interface - duh!). If you do get one make sure it has the correct interface for the hard drives you want to use in it.
The main advantage, so far as I can see, is you can hot-swap hard drives in it. You use uncaged, uncased drives.
It's versatile, but the quality really depends on the quality of the hard drive you put into it.
External USB hard drives are so cheap at the moment (1TB for £80 or so) and convenient that I would go for one (or more) of those.