I have both and use them for different things. The Go is good for cutting squares, triangles, etc where you do not want to have fusible on the back of the fabric.
The Cameo is great for cutting applique shapes. If you do machine embroidery applique, the Cameo is fantastic. You can use the embroidery design to get the shape into the cameo and have it cut for you. I bought my Cameo after seeing this post.