Despite working in 2007 I have still not seen any good reason to move beyond mdb/mde (2003) files. It is certainly far ahead on compatability and works on most systems.
A 2007 file cannot be digitally signed. That killed it for me. Hopeless oversight by Microsoft.
The whole accd* format is problematic because it is shared for 2007 and 2010 yet the 2010 files are not backwards compatible. The user remains unaware of the problem until they try to open the file in 2007.