This page gives the description of the layers available from the DC_GIS mapserver. When I look up the metadata for various layers, say record lots, the description says
Geometry Type: esriGeometryPolygon
but when I fetch the layer using either qgis or ArcMap, I get a raster layer. I've tried this for several different layers which describe themselves a polygons, but always get a raster.
In ArcMap I download the .lyr file. In qgis, I copy the WMS URL, open it in the New WMS servers dialog and select the layer to add.
Is it me or is it the metadata?