The main premise behind the 2" lap belt is one of added safety. A 2" belt rides within the crest of the human pelvis where a 3" belt would rest on the edges. This allows you to get the belt up to an inch and a half tighter. That means the lap belt will be working earlier in the accident event because it gets loaded faster. It's also more comfortable.
In the Hybrid belts, the 2" lap belt is configured as a Pull-Up, giving you the best leverage to tighten the belts. And because there is less friction in a 2" belt, it's easier to adjust in the first place.
The Hybrid style sub strap setup is a new technological breakthrough from Schroth. Each sub strap has a loop sewn in the end which wraps around the hardware for the lap belts. The lap belts then click into the cam lock and provide for a more efficient and comfortable transfer of energy to the cam lock.