I just found this a couple of days ago:
Good summary about the default configuration differences between NX-OS and IOS. Lots of people are familiar with the settings in IOS but NX-OS is often a new experience. That document is one of the must-read documents for those who are migrating routing from good old Catalyst 6500 to Nexus 7000.
In the document there is also a link to the IOS/NX-OS Migration Tool on cisco.com.