Best Way to Copy Data To External HDD

Hey all,

I'm about to reinstall Lion to try and improve my battery life (currently have an install that's upgraded from Snow Leopard), and I was going to back up all of my data so that I can copy everything back from the Users folder onto my new install and start right up again.

I was wondering if there's a difference between just selecting all of the files in my Macintosh HD and copying them to an external drive (which is what I'm doing right now) or restoring the internal volume to an external drive through Disk Utility (creating a Disk Image). I'm not really interested in being able to boot from the external, since I'm basically just going to drag everything from there back onto my computer.

So what's best?

(P.S. I'm not going to drag everything from Libraries; I really just want to copy over my User folder so that I can have all my old documents/settings right where I left them. I would think that leaving behind the system files and just transferring the User folder would have a positive effect on battery life)

 

I didn't think the files would really affect it, that's why I figured I could just drag them over into my fresh install of Lion. I'm running an early 2011 Macbook Pro 13", and my battery life was substantially reduced when I upgraded to Lion. I was thinking a fresh install would solve this problem.