I have the Go cutter and love it. There is very little fabric waste- depending on how you place your fabric on the die. I learned how to use the cutter by watching the free videos online.
I also don't find my Go to be flimsy at all. In fact, I was surprised by the weight and the solid feel of it. Like any tool, I'm careful on how I use it.
I don't make quilts as much as most of the posters here seem to but I love to sew and have used the Go to cut for many projects. The 5 inch square makes a great square for making coasters.