He's a decent enough singer I suppose, although I hate the quiff - but he's nowhere near as good as Jaymi from Union J if we're talking about singers in a boyband who are better than their bandmates ... he used to sing and the hairs on my arms stood up.
Although I did get more of a sense of a 'group' with Union J (even if they were slightly manufactured by the producers with the addition of George) than i get with SK, who seem more like 8 randoms put together on the stage.