The new adaptative layout allows to display each activities regarding their duration. The system does not change and stay as simple as it is since the beginning with cells to fill while dragging activities.
If you want to switch from the fixed to the Adaptative type, it is very easy, you just need to create a "blank" activity if you want to create offsets before activities.
Read the documentation here for a full explanation and screenshots.
The demo is back soon with a brand new site.