The Go is great for me. Honestly I haven't found one quilt pattern I want to make that doesn't have HST, squares, strips, or diamonds in it and the Go dies come in the most used sizes for quilt blocks. I have the Alto cutting system too. It's nice but it takes me longer to cut with it then the Go.
I never turn my nose up at new quilting gadgets or tools, it's fun to see the creativeness of them. If it's a new quilting tool, I want to use it. It may become my best thing ever or it may be in the next yard sale.