The Cog railway is defiantly the way to go if you want to visit the summit with small children. Tickets are pricey, but worth it. I have gone up on the cog a few times, more relaxing then driving yourself, and staff on the cog point out landmarks and give you a history lesson. Keep an eye out for wildlife, both times I went we saw deer. Once on the summit, they allow 45 minutes to explore, take photos, and get a snack at the cafe. The mac and cheese is very good, and the doughnuts are amazing. The 45 minutes goes quickly, they only allow that to avoid travelers from getting elevation sickness. Recommended that you bring a backpack with warm clothing to throw on once you reach the summit, even in the middle of summer with temps 80 at the base, it can be below freezing on the summit. I have gone in the summer and winter months, both required warm clothes, hats, and gloves. Drink plenty of water to avoid elevation sickness, better to go on a clear day, you can see four states from the summit if theres no clouds. Fun to go in the winter as well, they blast the snow off the tracks, so its like climbing up a wall of snow, if the weather is bad/snowy,windy, check to make sure they are going to the summit before getting your tickets, its not worth it unless your going to the summit!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC