The cloning notes are definitely the way to go. Just a few comments:
1. The source and target operating system release must be the same. Otherwise the binaries will not be compatible.
2. Depending on the release of tar, you have to ensure that the soft links are preserved. Older releases of tar would treat a soft link as a physical file or directory and would proceed to create a new copy. Issue the help command to verify how to preserve symbolic links.
3. If the adpreclone.pl was not run prior to "tar"ing the instance, you may run into some issues during the clone. In this case, I would strongly recommend that you log an SR with Oracle Support Services