The FD i30 has a reputation amongst dealers and repairers, of being a bit soft in the front.
This is because the chassis rails have a bolt on front extension that is made to collapse upon impact.
When this happens, the radiator support frame (made of metal and plastic) collapses into a pile of junk and the bonnet bends, destroying itself on its detent points.
The BIG positive is that in a minor traffic accident, the rest of the car may escape damage. The FD can be easily repaired by replacing the chassis extensions and other parts.
On the GD i30, I was drawn to the heavy chassis rails that do not have an extension. The weakest point appears to be well back in the engine bay, below the engine mounts.
http://i.imgur.com/MEMP9dO.jpgI can only reach the conclusion that the GD will probably take a bit more of a light hit, but, owners should look seriously at their insurance policies. In the event of a moderate accident, they will probably be requiring enough payout to buy a new car; because this car will not be repaired.