My kids love Mythos! The only issue I have with this restaurant is the service. It has been sub-par the three or four times I have been. Obviously not enough to stop me from going, but really not good service at all. It was slow, and was like your server was trying to avoid catching your eye - weird. We didn't go last trip and probably will not go in three days on our next visit.
By the way, I never consider taking my kids out to eat, fine dining or not, a waste of money. My kids love all kinds of foods, my son in particular loves trying new things that might not be on your regular kid friendly menu. My daughter is a bit more choosy, but she loves to try new appetizers. We sat at the table at Tchoup Chop that looks into the kitchen and they both had a blast. My son even ate the tartare (spelling?), that none of us would even try, and he loved it. My son is one of the reason I love to cook and try at least one new recipe a week - he is one of those kids that is so appreciative and a joy to cook for.