This is so great! Gridbeam looks like the perfect system to have for furniture in a household with kids!
I remember that I used to move around the furniture in my room on a bi-weekly basis when I was ~7-10 years old. Bi-weekly meaning between once every other week and twice a week, depending on my mood. :P
But moving stuff around was about all I could do. It would have been soooo cool to be able to actually change the furniture!
Building this way is so fun. Given that it's modular, when we try it and go "hmm, maybe this would be better if it's lower" then "how about we saw the legs down" is like an expected response. With a traditional bed I would probably never thing that.