I don't wear running shoes, so I can't comment on that. I love the NB casual sneakers though. Service is quite friendly, and they can figure out if other locations have your size very quickly in store.
The downside is that they almost never have sales, at least from my experience. The only time of year I know that they have sales is their boxing day sale, which runs for a few weeks straddling boxing day itself, I believe.
FYI - Selection in-store is larger than online. Use the website as a rough guide, but don't assume that it's their entire inventory.