After a very short test I will say the following.
Under normal circumstances you can zoom in with the optical stabilizer on and capture an image that you might otherwise miss if you had to set up a tripod. It seems to be good if you were to take photos of sport or wildlife. It's usable in failing light up to a point, beyond that you need a tripod.
You can't beat a tripod if you have the time to set one up.
It's another tool to have in your bag, good to have if you need it, but not essential.

The lens is quiet with the OS off, a little noisy and jumpy with it on.
After using the kit lens I find that I tend to move the focus ring unintentionally. It can't be doing it any good when it's in AF.

I reserve the right to change my mind as I get used to it