Best compressed archive_command on Linux?

I'm in the process of moving an 8.2 server from Win32 to Ubuntu Linux.
On Win32, I implemented WAL archiving with the archive_command
"rar a -ep -m5 -s -t -dh w:/%f.rar %p"

Anyway, I'm going to use WAL archiving on the new server, and need the
files to be compressed. My first inclination is to use
"tar -czf /walarchive/%f.tar.gz %p > /dev/null"

Before I go with that, though, I was wondering if anybody had any
specific experience / advice with a better command, reasons why this
command might fail zero or succeed nonzero, or additional/different
options for tar that would yield better results.

Thanks,
Sean