I spent the best of a weekend putting it together. I could have done it quicker, but my son was helping. It was his mainly his idea.
I don't really save much time. The real benefit is knowing that the food won't burn. Growing up my mother would make soups and stews, she'd leave them to simmer for 30 mins without checking. The food on the bottom of the pot would burn and make the whole thing taste nasty. I wanted to make a system that would prevent that, whereas my son just loves building robots and playing with motors.
It was as much a project for me and my son to mess around with as much as an actual kitchen time saver. But we have plans to develop it and just see where it goes.