If you do not already have the Elite Pack : Digital Sound Factory Vol 1-13 for Dimension Pro/Le (
http://www.store.cakewalk.com/b2cus/ProductInfo.aspx?productid=10-DSEP1.00-2RE) then the Complete DSF Sound Pack Bundle for CW Sound Center is really worth it, especially with the current 26.2% promo.
Some time ago after purchasing the Elite Pack Vol 1-13 (Dimension), I wrote to DSF and ask about these 2 packs, and got a reply that most share the basic wave forms, so for Sound Center, you get immediate working sounds with it's great sound type classification info. If you are looking for sounds without tweaking much, then the Sound Center pack will be most suitable.
Now, here is the thing.. after I've got the Elite Pack Vol 1-13 (Dimension), and for woodwind/brass arrangement work that I do, although I can find most sounds in the DSF, I still get the Garritan Jazz library for more complete woodwind/brass sound.
For anything else, I'm happily using Dimension Pro and the DSF Elite Pack.