sorry for my late answering,

I agree with you julian, if i take the ora-doc 8.1.7.
The hint for non-shared environments has been taken out.

HINT -> ORA-DOC8.1.5/Oracle8i Parallel Server Concepts and Administration
Even in a non-shared environment, multiple free list groups can improve performance. With multiple free list groups, the free list structure is detached from the segment header, thereby reducing contention for the segment header. This is very useful when there is a high volume of UPDATE and INSERT transactions.

Additionally, we discussed this issue on the german Oracle User Group (DOAG) Meeting in november 2001. It has been checked by more consultants then me.

armin (merry christmas ...)