This is a comprehensive comparison, if you are on the fence about whether to publish through CreateSpace or Lightning Source. I personally have published through both and will add that CreateSpace is a more “user friendly” site than Lightning Source. It is basically your choice and preference.

The one big difference, as she points out in this blog, is that Lightning Source does offer the return policy, which CreateSpace does not.

Source: The differences (however slight) between CreateSpace and Lightning Source paperbacks