"This is the right idea. Yes, you should be prepared for Zombies, but you must also prepare for everything else that goes along with it.

Humans - refugees (ranging from peaceful to starving and desperate), raiders, legitimate military/police
The conditions of a post-apoc world (food, water, supply, medical emergencies, etc)
Radiation - bombs or plant meltdowns
Natural Disasters (including those that hit post-apoc) - Tornado, hurricane, earthquake, wildfires, etc

So, it really doesn't matter if the Zed are slow or ragers - bullet to the head and dead. What does matter is if I can shoot starving humans who have fled the cities (I can't feed them all). If I can survive a worst case wind scenario mixed with a meltdown at the closes nuclear plant or the bombing of the closest major city or military post. If I can protect my house from fire, rebuild or relocate from storm, or feed my self and family for now and preferably the next two generations."