I have the Stofen Omnibounce as well and I find that it is not even as good as the now obsolete LightSphere II. The Stofen can only be used to take wideangled (or zoomed) shots from a distance eg like in wedding dinner photos. If I had used it to take close-up shots like in these portrait shot of my cats from a distance of 2 to 3 ft, the shadows cast would be just as bad as if I didn't use a diffuser. The Stofen also reduces the reach of the flash a lot more than the LSPJ because it is translucent while the LSPJ is practically transparent.
The LightSphere II PJ is better that its its older brother and is even better when used with the inverted dome accessory that was specially designed for it.