I have worked with OpenERP (now Odoo) since 2009. I was a core contributor at the time as well.

I understand the questions is old, but I'd leave an answer here for anyone who might stumble upon this question.

I would recommend you to consider Tryton - a fork of OpenERP (also Open Source). The project is supported by a not-for-profit foundation (like Mozilla Foundation for Firefox) and is relatively a better quality project in terms of modularity, code base and ease of development.

Happy to assist anyone who is considering an Open Source ERP system for their business.