Database migration across platforms of different "endian" (byte ordering) formats using the Transportable Tablespaces (TTS) process has been certified for Oracle E-Business Suite Release R12.1 for several years.
This certification has recently been updated to cover the use of the incremental backup option with Database 11.2.0.4 as a source.
Does it meet your requirements?
Note that for migration across platforms of the same "endian" format, users are advised to use the Transportable Database (TDB) migration process instead for large databases. The "endian-ness" target platforms can be verified by querying the view V$DB_TRANSPORTABLE_PLATFORM using sqlplus (connected as sysdba) on the source platform:
SQL> select platform_name from v$db_transportable_platform;
If the intended target platform does not appear in the output, it means that it is of a different endian format from the source and Transportable Tablespaces (for large databases) or export/import should be used for database migration.
The use of Transportable Tablespaces can greatly speed up the migration of the data portion of the database - it does not affect metadata which must still be migrated using export/import. We recommend that users initially perform a test migration with export/import on their database with the 'metrics=y' parameter to find out the relative size of data vs metadata in their database and to have a basis to compare any gains in timing. Generally speaking, the larger the relative size of data (as compared to metadata), the more likely it would be that XTTS is suitable to reduce downtime.