well, its exactly as u said, beautiful but boring, the case is same with even Saint Rows 2, its pretty and boring too. the thing is this tends to happen with free-roam games a lot.
The only exclusion i can say is "Mafia" and "GTA" series, GTA is so awesomely-superb because of its voice-acting and beautiful and funny story/lines/scripts (Like in lost and damned a guy says "I've been riding this bike before your mom rode your dad", now THATS funny). And as for mafia, i loved it a lot, but there wasnt amazingly free roam capabilities though.... waiting for mafia 2 eagerly