The Canton location has expanded to downtown Baltimore. Just got back from lunch. It's a strange location--a desolate block of Water St between Commerce and South--but it makes for peaceful surroundings since there is virtually zero street traffic. It's in the Randstad building so you can get to it through the Lombard entrance if you want.
It also took me awhile to figure out from their marketing whether you could come in and eat one sandwich or if it was just catering. Even walking by you can't really see in the place. But there are about six tables inside to sit.
The sandwiches are great if a little pricey $7-10. Definitely a place that pays close attention to every part of the sandwich (esp. bread). Full menu online. A great addition to the scene as my Au Bon Pain/Java Joe's rut is getting deep.