comparison ADF vs OAF

Oracle recommendations 

If you want to integrate your extensions tightly with the E-Business Suite,
you should use the OAF Release 12 technology stack, which includes the
use of JDeveloper 10g and ADF BC (or use OAF Release 11i, which uses
JDeveloper 9i).


 If you are building a separate application that does not integrate tightly
with the E-Business Suite, but needs E-Business Suite-specific capabilities
like Flexfields and personalization, you should use the OAF Release 12
technology stack. If your application does not need to integrate with the
E-Business Suite, or doesn't require any of the E-Business Suite-specific
capabilities enumerated above, you should use ADF 10g with SOA based
integration with E-Business Suite.


 If you are building a separate application that does not need to integrate at
all with the E-Business Suite, and you need an AJAX-style rich client user
interface, you should use ADF 11g.

Source : oracle support