This is a good idea, but the current implementation seems to suffer from a problem: it doesn't preserve the mod times of directories in the archive when it creates the archive. For a test, try the following:

xtar cf - /bin | ( cd /tmp ; xtar xvf - ; mv /tmp/bin /tmp/bin-xtar-xtar )
tar cf - /bin | ( cd /tmp ; tar xvf - ; mv /tmp/bin /tmp/bin-tar-tar )
xtar cf - /bin | ( cd /tmp ; tar xvf - ; mv /tmp/bin /tmp/bin-xtar-tar )
tar cf - /bin | ( cd /tmp ; xtar xvf - ; mv /tmp/bin /tmp/bin-tar-xtar )

ls -ld /tmp/bin-*

You will find that both of the versions created with xtar as the starting command result in directories in /tmp with mod times (incorrectly) equal to the time at which the command was executed. The versions start with regular tar produce directories with mod times correctly set to the times of the original directories.

This needs to be fixed before xtar can be used.

Testing performed on a MacOS 10.3.3 system, latest security fix (2004-04-05), on a desktop G4 dual-processor.

MH