Perhaps it implies that you've extracted those names into some kind of constant or configuration object or view model that you're using throughout the system; i

Perhaps it implies that you've extracted those names into some kind of constant or configuration object or view model that you're using throughout the system; if they change, you change them in one place and the square bracket version keeps working. I personally find it more useful to deal with forms using some kind of abstraction on top so I doubt I'd use either variations in anything other than a very simple page.