Depends on who you ask, but I, personally, think its a great time to go. We've done that week several times, and I love the low crowds and typically milder climate. That said, we contend with ride closures, shorter nights, and the potential for bad weather (usually bring jackets, etc.). So, its all about what is important to you. For me, lines is the main thing - we don't like lines. So, if we can, we go during that time (late Jan, early Feb), because of the low(er) crowds.