Which is Better for Backing Up Clients?

 We have several xp and 7 workstations that I would like to back up select files. Right now we have scheduled windows back up to weekly back up these folders but I would like a better way to do this.

 I have read some about Symantec DLO 7 and we also already back up our servers with back up exec 2010 and have read how I can get 1 RAWS agent per workstation and it will back up select files.

 What is the difference between the two? Do they both allow us to select files to back up? What advantage does one have over the other? Im thinking since we already are using back up exec that the cheapest thing to do is just purchase RAWS for additional workstations we want to back up. Any info I'd appreciate.