We've dined there when our girls were 4 and 5 years old, and they were fine. We went over the rules with them ahead of time, and they knew how they were expected to behave, and did just fine. I believe they had crayons to draw with, which kept them entertained during the slower parts of the meal.
It is definitely more of an adult atmosphere, but well behaved children appear to be welcome. Only you can make the decision if its a good fit for your kids.