First adventure has gone really well and the whole family (with kids of 4 and 8) is revved up for more. As GM I chose to be pretty flexible on the details of turn-taking, movement etc, for the sake of smoother game-play; I don't think the system as written is clunky, I just found the more organic approach worked better for us.
My only criticism is that the introductory adventure, Basement O Rats, is a bit too repetitive. After the first encounter my 4yo was already declaring himself sick of rats. But I'm looking forward to trying out other adventures, and inventing our own. (The 8yo is highly impatient to try her hand at GMing!)
[4 of 5 Stars!]