With kids, give Chicago Architecture Walking Tour a miss.
The CAC's docent-led Loop walking tour is the on-foot counterpart to its river cruise, and the choice between them is real: the cruise gives you the sweeping 50-building skyline panorama from the water, seated and weatherproof; the walk trades breadth for depth — fewer buildings, but you go inside lobbies (the Rookery, the Marquette) and stand at street level reading the stone up close. Take the walk if you want detail and don't mind two hours on your feet; take the cruise if you want the big-picture orientation. The honest catch is the walk is slow-paced and weather-dependent — a delight in May, a slog in a January wind.