The features I have found to be most helpful over other cloud storage platforms are:
1) Collaboration - just not that it exists, but it is easy and user friendly. Allowing data that is necessary to be worked on to be brought to the surface.
2) Security - focus on compliance, encryption, enterprise grade management.
3) 3rd Party Integrations - allowing for Box to truly be a platform to be used with other software.
I think the workflow engine they just added will be another valuable feature