I would definately go for Teppan Edo. The food is fresh, good, and they have decent portions. With young kids, the entertainment/ cooking will keep them entertained and calm throughout the meal. With such a fun atmosphere, your kids would probably enjoy it.
Chefs is just plain bad. Teppan edo is very bland and the portions can be hit and miss due to the way they do it. We weren't impressed with either but if I had to pick one it would be teppan edo
I think the number one consideration in picking between these two is appropriateness for kids - Teppan Edo is extremely good and Chefs is extremely bad in terms of 'entertainment value'. I would rate the atmosphere at both about the same: that is, they are both well-themed for what they are supposed to be. I believe food quantity is not huge at either but Teppan Edo may have a slight edge. Food quality - ask 2 people, get 3 opinions; base your choice on your menu preferences.