Different analysis, different tactics, different approaches. But the problem is that those who rail against "insurrectionary" anarchists are almost always using a strawman argument. The insurrectionary anarchists I know do not ignore, dismiss, or otherwise disregard a class analysis of capitalism and the state. Those who refer to themselves as "class struggle" anarchists are almost always using that terminology as a short-cut way of describing their strategies and tactics. More specifically it appears that they do not reject labor unions as locations for revolutionary intervention, whereas most other anarchists (and not just the crazed insurrectionaries) do. Perhaps the main distinction is manifest around the organizational question; class struggle anarchists tend to favor formal membership-based cadre organizations, while insurrectionary anarchists reject them in favor of networks and informal ones.