Roger Zubrinich1 wrote:
Which is best - using setup assistant to migrate files directly from my old iMac or from a Time Machine backup?
There really is no practical difference. Use whichever method is convenient for you.
My current computer is set up with two accounts with different passwords. Will the passwords for the accounts and the admin password be transferred to the new computer so there are no issues with logging in?
Are there any potential issues I should be aware of?
Rosetta does not exist in Mountain Lion. Therefore no old PowerPC programs will work.
Use a wired connection - you can connect the Macs to each other directly or through your LAN, but avoid wireless. Wireless can take an unacceptably long time.
If you are impatient and want to use your Mac right away, and therefore want to defer migrating your accounts until you use Migration Assistant later, then do not create an account with the same name as an account you wish to migrate. In other words, create a temporary "throwaway" account that you can delete later. Use this temporary account for the sole purpose of initially playing with your new Mac, and for migration of the previous user accounts you will actually use.
If it is an Intel Macs you can use Migrayion Assistant:
How to use Migration Assistant:
Troubleshooting Firewire target disk mode:
If it is a PPC Mac:
Migrating from PPC Macs to Intel Macs:
Personally I would create a bootable clone using either SuperDuper or Carbon Copy Cloner and restore from that using Setup Assistant. If you don't want to go that route than the next best thing is using your Time Machine backup. Everything on the version of the TM backup you use will be migrated including all accounts, settings, apps, and user files. You may have minor issues that require reinstalling some apps, for example if you use iWork or MS Office you may need to reinstall those apps.
Also remember any old PowerPC (PPC) based apps will migrate but they will not run in ML so you need to either replace or update them prior to migration.