My 2 cents worth. Having recovered from a server crash caused by a faulty UPS, I can add the following experiential info.
Robocopy (or in my case xcopy) does just that, copy files. There is no rollback, versioning or 'aggregation' into a "system specific filetype." The huge problem was, of course, in order to read the server backup files I needed an operation server2003 system, which I didn't have because it had just crashed, and being a small administration, only one server was ever installed.
Thus the huge .bkf files created by server2003 backup were unreadable on any other system.
I had, thanks to foresight, used a simple xcopy command in a batchfile to copy all user files to an external harddrive, and after the crash was able to still provide all these files to the users.
It makes sense to do BOTH, system specific backups, that will require a functioning system to read and reinstall from, AND a non-sytem specific open COPY that can be read by any other operating system, for just the scenario where the system that was supposed to be able to read the backup files isn't running.
Now I have a server with RAID 1, against single HD failure, incremential server backup twice a day to a 3rd exclusive HDD, and an RDX with 5 cartridges for rotational simple copy of user files, plus regular complete system back up to RDX in case of requiring to rebuild the system on other hardware. The cartridges are kept in a fire-safe.