It is also better than Google Maps in some ways:
- It has more details: it shows footpaths, rivers and streams, wooded areas, and paths across parks. It has outlines of interesting buildings where people have entered data for them.
- I think the default renderer (Mapnik) looks better than the Google Maps equivalent, especially when zoomed out to a level where streets are one pixel thick but still distinguishable. Google Maps gives too much prominence to the major roads -- it renders them thickly, in bright colours, and with large labels, which tends to drown out the details. Mapnik is more subtle. The map just looks more interesting.
- It uses more of the browser window and doesn't waste as much space on sidebars. It's almost a trivial point, but it makes a difference.