YAWL workflow

What is the most frequent requirement for a workflow system? Is it BPMN conformance? 

YAWL is not BPMN. We would like to make YAWL better than BPMN. Having fewer constructs with a similar expressivity is certainly an advantage. Using colours instead of swimlanes like in the attached figure certainly saves a lot of space.

We would like to get your opinion on this topic. Just post on this forum or send me an email.