+1 from me too. It doesn't really have to be cubic either, but it should be dynamic in such a way that the infill density is higher where needed, and less where not needed. A good example can be seen in this video: https://youtu.be/CJ2F-YjHe2k?t=3m1s
For example, printing a half dome would need very little infill towards the center, but higher density towards the outer shell. If S3D could make this automatic and dynamic it would be awesome. Using multiple processes can achieve something similar, but it is a lot more work to set up.