Deployment strategy PowerBI

Hi - 

just planning an enterprise deployment of Power BI and evaluating different options. 

As I understand there are different ways to share your apps and how you set up security: 

Lets say we are talking about an environemnt with 50 User and 10 Apps. 

Deployment options:

1- Developer/Admin prepares dashboards and publish them directly on the power bi cloud. Security is handled via Roles and Mail adresss.  No gateway required for users (data source is sql db)

2- SSAS layer between the SQL DB and PowerBI. We create a enterprise gateway and user connect via live connection to SSAS. Security is handled through SSAS. 

Could you let me know about pros / cons fo these options and overall what would be the best deployment option?

Thanks