Thanks for the input, all.
Lono -- Hadn't thought of that. A very good tip!
And yeah, it does boil down to what one is most experienced with, doesn't it?
Myself, I learned to cross country ski first (a.k.a. Nordic skiing), and have done so since childhood. Downhill (a.k.a. alpine) skiing on the other hand was more of a post-college activity that was only done once a season or so, and less than that now that lift tickets cost the moon.
Snowshoeing experience is somewhat less, as well; mostly something I did at scout camp with old-school ashwood and rawhide gear; I've not yet tried out the aluminum variety, but am very interested now that I've seen how compact they are.
The reason I was asking which was better for an urban situation, I suppose, is because I could totally see myself XC skiing, due to ease and speed, but then thought that there might be a snowshoeing advantage that I'd be missing out on -- and now this has been confirmed by the helpful posters here. (More maneuverable in tight spaces, easier to store, etc.)
I'm thinking my scouting experience of clumsily trudging in oversized tennis rackets might need an update...