I have a Zum (for the 2) and an Incipio Feather -(also for the 2)
The existing Zum 2 - will go onto the 3 - but it doesn't quite fit properly side to side.
I would say the Zum offers a good deal more protection to the exposed edges and corners of the iPad than the Feather...however...whilst it possibly seems more substantial and thicker than the Incipio - the material is not particularly strong....the one I have on my iPad 2 has all the corners broken off - and several cracks from some fairly limited and light impacts - so I think it looks the part but I am not convinced it will give much, if any, protection in the event of, say, a drop from waist height onto a hard floor.....mind you neither would the Incipio....
So for day to day light wear I think I might wait for the Zum....just wish they would use a more robust material to make it from...
Is the feather made out of better material?