yes, but as you saw on a6 and shaders on blocks, there might be some technical burdens to overcome at first.
and xReal_preAlpha cannot hide that their shadow mapping algorithm is slow as hell, while stencil volumes went like greased lightning. and not all maps are of equal quality.
interesting as well, they support doom3/quake4 md5mesh and md5anim, and even deliver an exporter for blender (py scripts). a modified gtkradiant version is included, too.