I'm not one for staying overnight at an AMC hut, but they certainly make the hike easier, particularly going through the Presidentials. They are avoidable, but as previously stated that usually means a detour off the ridge of about 1 mi and 1,000 vertical feet. If you are interested, there are a few different ways to do it, depending upon how many days you will take to do the Presi traverse. On the other hand, there is nothing wrong with staying in the huts if that is your preference.