I didn't get the machine, but it appears to be just another version of the Sidekick - different manufacturer. The sidekick is extremely easy to use - as long as you can line up the layers properly. I would certainly think that a 6 or 7 would be able to handle it after a bit of instruction from Mom.
You just put down a cutting pad, put on the die (foam side up), put the paper on the foam, top with the other cutting pad & roll through the machine. For children to use, I'd think the easiest thing would be to either buy those pads of paper that are already the size of the dies, or pre-cut it for them.
I'm starting a separate thread with a question about CuttleKids dies - they don't have a layer of plastic on top like Sizzlits...it's cardboard & I'm wondering how well that holds up. You may want to check to see what others have to say about it.