The comparison of different OSM compatible applications on Android over at the OSM wiki page is somewhat outdated. A lot of features (like vector maps) are missing from the tables. Someone with more knowledge of the full feature set of Locus should update this page. Note that the features table are dynamically generated from the individual application wiki pages. This is the page that should be edited:
http://wiki.openstreetmap.org/wiki/Locus
http://wiki.openstreetmap.org/wiki/Locus