Odoo's framework is unique. It provides top-notch usability that scales across all apps. Improvements to the framework are applied to all of them. That way, Odoo evolves much faster than any other solution.
Odoo 12: Improved Accounting, MRP Module. New view: Cohort and activities. New Apps : eSign, IoT box
Odoo 11: Python 3.xx (Upgrade from Python 2.7), 3x faster than Odoo 10, New Apps : Marketing Automation
Odoo licenses are amongst the lowest compared to similar solutions. It is the result of a philosophy:
Integrated: Fewer complicated third-party integration
Transparent pricing: you only pay for what you use
Customise your database to your unique needs:
Extend: Add new fields or business logic to automate your processes
Application Builder: Use odoo framework to develop new unique business Apps
More advanced Apps (e.g. Quality Management, Rental, Accounting Consolidation etc..) and dedicated services are available to Odoo Enterprise Users:
Odoo Support Team
Guaranteed source code upgrade 
Odoo Cloud 
Alitec, and Odoo, the software editor will work to ensure the long term maintenance and usage optional
Highly customisable, Odoo requires a strong infrastructure to confidently test and deploy new features, as well as scale up with usage.
Odoo Cloud is the editor's full-stack platform with back up, monitoring, scalability and 99.9% availability.