I have been working on the ODATA functionality in Dynamics AX 2012, and found there is some pitfalls in the tool. Together with one of my developers I have created a service called ODATA Proxy service that enhance the functionality of the standard Dynamics AX ODATA Query service
Working with AX2012 has many times left you with a model store that looked like a mess. Various elements was accidently placed in the wrong layers and models.
When installing SQL 2014 components you can run in to an error, that you cannot install the SQL tools like SSMS or SSIS.
Even though AX2012 RTM and R2 is official supported with SQL2012 Always On setup, I have found some issues related to this when developing on this setup.