Like others I use Photoshop everyday for all of my 2d graphics work. I have never used Candy Factory.
I downloaded the examples and I think they are crisper and clearer than the results generated using Photoshop. The lighting effects look great.
What would be nice is to have a before and after shot.
I mean if these started as a plain b/w image then it looks to be a 'must have' product.
Of course similiar effects can be generated in Photoshop but it would need a lot of planning and head scratching.