I thought they were very good. Easily the best group, and made Nu-Vibe look like a dire bunch of pretty boys. Can't see Nu-Vibe lasting longer than The Risk, but you never know who the all-important teenage fangirl voters are going to go for. The Risk is a good looking group, but Nu-Vibe seems like One Direction, in that they are primarily designed to be eye candy for girls between the ages of 12 and 17. The Risk will have teenage girl fans as well, but they'll probably have an equal amounts of middle aged mum fans.
I hope they don't just make Derry do an obligatory rap all the time. It was obvious on his singing bits that he's easily the second best vocalist/singer after Charlie, and could carry a song strongly. They should alternate lead vocals between Derry and Charlie to cut out any accusations of being a "one man band".