The 'Amb' partly comes from Ambrus's first name, but it also reflects his affinity to ambient. Of course it doesn't mean he makes this genre exclusively. His detailed and deeply emotional music is frequently used in theatrical productions, but you will find dancefloor beats just as much as 'armchair' melodies in his repertoire.
Although recently he's been more into breaks/nuskool, Amb will give you your 4p4, downtempo, or ambient as well, for that matter. No doubt he doesn't depend on genres at all, (which is also a principle at Chi, by the way). His songs are characterized by softer textures over strong grooves and a corking bass. And did I mention his live act with Raster? When they go Raster&Amb, the crowd starts to move and nod severely. Yes, in fact, Amb is everywhere.