Upgrade horror stories/victories

I am looking for the opinions of anyone who has had the following experiences

Upgrading from Oracle 7.3.4.2 --> 8i
Migrating from Oracle on Windows NT --> Some UNIX Flavor

My company has high transaction IVR system that is attached to an Oracle RDBMS (7.3.4) which is running on a DEC AlphaServer 2100a with Windows NT 4.0 SP6.

7.3 --> 8i: Ive heard that Exp/Imp is the safest way to go, but you've got to have plenty of time, (which I do not have) and disk(Which is easy). The MIG80/Oracle Migration Assistant utility is fast, but can be known to crash and burn, which leaves you to restore the backups that you should have made prior to the upgrade.

NT --> UNIX: Is the migration really worth it? The current database on NT does not perform badly right now. Does going to a UNIX flavor (Solaris or DEC UNIX preferably) offer significantly greater performance enhancements? The reason we are evaluating this is because of Compaq/Digital's recent announcement of no longer supporting the Windows flavors on the Alpha platform. With this news, I personally do not feel the Intel stuff is up to snuff for an NT/Oracle combo. (but I could be wrong).

Any experienced opinions would be greatly appreciated.

Andre Allen
--

  .:'`':..:'`':.. Andre T. Allen ..:'`':..:'`':.   |  Disclaimer:  |
 |             andre_at_interaccess.com            |  | All opinions  |
|  Systems Admin/Oracle 7 DBA/MS-SQL Server DBA  | | expressed are |
+------------------------------------------------+ | my own.       |