Rsync and Compression

[WipeOut]

Hi,

I have created a script that will backup some files from my web server 
to my local server via the internet.. I will be using Rsync over SSH..

I am unsure of the best way to impliment compression since bothe Rsync 
and SSH have the ability to compress data..

The options are either to use rsync compression..

rsync -z --rsh=ssh ...

or ssh compression..

rsync -rsh="ssh -C" ...

My thinking is that the Rsync compression would probably only be 
effective if I was communicating with an Rsync server but since I am not 
it would probably be better to use the SSH compression since SSH is 
providing the transport..

Can someone confirm or deny this? or correct me if my thinking is flawed..

Thanks..