I will be upgrading my production database from 9.2.0.1 to 9.2.0.4 Saturday night. I will have plenty of B/Us.

Do you recommend creating a new Oracle home for the 9.2.0.4 binaries or just upgrade the current Oracle home ? I can always reinstall 9.2.0.1 and go back from a cold backup.

Here is my experience - I did not create a new Oracle home for any of these:
1. Development upgraded very easily
2. QA was a nightmare due to a corrupt JVM..
3. Eventually I cloned production into QA and then the upgrade went very smoothly (this gives me big confidence that the prod upgrade will work).

Thanks