[CentOS] Copying CentOS to new drive

I recently asked about copying a running system to a new drive.

As a postscript, I'm wondering if it would have been preferable 
to run the machine under a Live OS, and simply copy the root partition
to the new drive?
Eg while running under the LiveOS,
  # mkdir /mnt/old /mnt/new
  # mount /dev/sda7 /mnt/old
  # mount /dev/sdb6 /mnt/new
  # cp -avx /mnt/old /mnt/new
or
  # rsync -ax --progress /mnt/old /mnt/new

-- 
Timothy Murphy  
gayleard /at/ eircom.net
School of Mathematics, Trinity College, Dublin