Believe it or not I haven't tried any blending sponge, well other than those white triangle ones. JGOB has a cute variety of blending sponges (*). I was able to try out the black one. The one distinction for other sponges is that it has its own carrying case. Once the sponge it dry I recommend storing it in that container as much as possible to prevent bacteria as well as sponge breakdown.
Right out of the package the sponge is smooth has no edges and is squeezable. From what I understand some of the non name brand sponges are hard out of that package.
I used this two ways. With and without water. When you rinse it with water the sponge becomes quite large. I think the benefit to this is that it will soak up less of your foundation and keep it on your skin. I liked this application best, while the dry application wasn't bad and worked well, I feel I saw a difference in smoothness of my makeup.
When you apply foundation with this sponge, it gets into smaller areas nicely. Don't forget to wash after every use and let dry in a week ventilated area. One last positive is the price compared to other brands!
* I received this product in exchange for an honest review.