SAVLIB SAVACT(*SYSDFN)

We acquiesce our systems (except for an extremely rare job or two) to do 
our backups.  Instead of skipping critical objects (current technique) 
that are locked by these particular jobs we thought of changing from 
SAVACT(*NO) to SAVACT(*SYSDFN).

What concerns (if any) should I have?
- Will it increase the overall length of the save like getting to 
checkpoint status or some such thing?  Although I believe that *SYSDFN 
says no checkpoint processing is done.
- Instead of skipping the object, will it now save it?
- Instead of skipping the object, will it now wait forever for it to free 
up?

Other information:
No journalling.
"Hopefully" low probability of out of sync files by these particular jobs. 
 Meaning the odds are low that the job would be stuck in between an update 
to the order header and an update to the order line.
IFS usage by these jobs is nonexistent.
These jobs are not expected to be a nightly occurrence.  Therefore a few 
nights a week the object in question is currently backed up.  Just skipped 
on rare occasions.

Rob Berendt