I would chose an AR over an AK for your intended purposes, but I am of the perspective a rifle has fairly limited practical applications in civilian self-defense roles such as when you have a lengthy lead time and/or have taken a fixed position such as in a safe room or similar scenarios. 5.56/.223 makes more sense than 7.62 x 62 for a home defense carbine or "urban rifle" irregardless of which platform is chosen. I think first getting a high capacity semi-automatic pistol for home and carry would probably be more useful than a rifle for the scenarios that would be most probable.
And keep in mind that active shooter cases and terrorist attacks although high profile media stories, are extremely rare here. The scenarios civilians are most likely to encounter(armed robberies, physical assaults, muggings, car-jackings, rape attempts, home burglaries) can all generally be resolved effectively with what you already have. As a civilian, it is not your job/responsibility to proactively respond, engage and pursue like the Military/Police.
I asked Massad Ayoob his opinion on AK's. Here's his response...
"Generally clunky, mediocre accuracy, crappy ergonomics. The best AK I've seen is the American version by Arsenal, Inc. (don't have the address handy, but Google should, I think they're in Vegas.) Their .223 version is particularly sweet. However, prices are comparable to low end ARs like the DPMS Sportical, which is a much better rifle, or the Ruger Mini-14 , ditto."
And here's a quote from Clint Smith from the 2008 issue of American Handgunners Personal Defense magazine.....
"There is somewhat of a myth promoted that an AR or AK rifle is mandatory for personal defense. For the cops and military, in the infantry-like environments in which they function, I think a rifle is helpful. For civilians, the need for a combat rifle could be a reality, but I often think it is simply a well-developed sense of something else. The public-some of them-sort of wants to play army or cop if they can and buying the gear helps make the dream come true."
