Less Cardiffy would be good. There's nothing wrong with Cardiff. Cardiff is a nice place. But they did slap it across our faces every two seconds, which was a bit much.
I did think it was funny how a character visited the fictional museum of natural history at Aberystwyth University in season one -- a parallel universe where Aberystwyth is a real university with a museum! It would be nice to have more of Wales in there. "Why do aliens always attack America?" could also be phrased as "why do aliens always attack England?"