They expect a lot from you, especially as you move through the manager and principal ranks, requiring you to learn and become proficient in several new sets of skills (project management, team leadership, mentoring, executive presence, etc.) over a couple of years. This means that you will likely have to put in time above your traditional 9-5 to manage your workload. It's not a 70 hour work week, but 45-50 is expected and normal. Starting with the Manager to Principal promotion, you are required to complete a "Point of View" presentation, which is sort of like a Master's Thesis. This is in addition to your normal responsibilities of leading an important client project (and for many people raising young children). This has definitely become a choke point in the growth path.
Also, like all consulting work, your experience may very based on the project you are assigned to. Because of the local model, some clients may be in the "same city" as you but actually be an hour or more from where you live.