I'm working on a Magento site upgrade from 1.5 to 1.9. Currently, we have a development/staging site set up running 1.9, that originally had a complete copy of the production database.
However, obviously time has passed, and the customer data is out of sync from production. Additionally, we've made configuration changes to the dev site as a part of the 1.9 migration.
How do I go about transferring customer information (but not configuration information) from Production to Dev so that I can switch over by pointing DNS at the dev site?