On my previous phone (an HTC Desire), I had a gel case which worked very well and with my new Galaxy S3, I wanted the same thing. The case fits perfectly and there are a couple of things that distinguish it from previous gel cases I've had: 1) The case is proud of the camera at the back which means the camera glass is less liable to get scratched. 2) The case is much easier to click in to place than other gel cases I've had, there's no feeling of having to force it round the phone. It's also easier to get off which is very useful because I think I'll be taking it out of the case more often to dock it. 3) It makes the phone feel more secure in my hand and less likely to slip out.
It's slightly brighter and a more electric blue than I expected, but it's fun and it stands out so I'm fine with that!