I outgrew my brother CS6000i and gave it to my niece and nephew (8 & 12 years old at the time) and they have no trouble working it. I demonstrated changing the needle and threading it once, then unthreaded & took out the needle and made each of them do it themselves and now they're sewing machine experts! (So they told me, LOL)
I liked the machine myself and would have kept it as a travel/backup machine but I was happy to give it to them too. I think it's great that they BOTH are enjoying sewing. They've had it for over a year now and I get periodic reports that they haven't broken it yet, although I did hear they successfully sewed some cardboard together with it, LOL. The things kids think up....