>1)is level zero backups on Unix so hard to initiate that they're right in say-
>   ing that's its very little effort to include all the data (system & user)??

No, but in order to get a consistent usable image, they need to be in single
user mode, which effectively makes taking a level 0 dump a
extended outage for the users. If you're going to make such an
image, you might as well do OS and data periodically while
everything is shut down.

>   (i.e. is there an easier way
>    of creating a 'bootstrap' backup that could launch them into running ADSM
>    for a disaster recovery scenario?)

Yes. Most Unix install utilities include a special version of the
kernel that does not involve swapping at all (on Suns, this would
be called the "miniroot" boot). You can boot the miniroot,
repartition and format disks, install ADSM, and restore the
remainder of the system using this configuration -- it has enough
network and kernel support to allow the disaster recovery.
Smoking ruin to restoring files usually takes about an half an
hour to 45 minutes after getting the parts replaced if the Unix
jock is reasonably competent. Restoring from a level 0 backup
takes about the same amount of time.

>    2) better / more up-to-date backups if ADSM is run twice daily compared
>       to level zero backups run every X (where X is every day/week/month)
>    3) ease of use for individual users on the server (there maybe no users)

User-initiated restores with no system administrator
intervention.

User-initiated reversion to earlier version of files w/o
administrator intervention.