I lived in England for several years, so I've seen this show. I loved it. In fact, I loved it more than American Idol. Here's the set-up:
There's no upper age limit for contestants. They are divided into three bunches--younger, older, and groups. Each bunch of contestants is mentored by a judge. The judges are assigned to a group by the producers, after the auditions are over. This means that the judges have seen the talent and can wish for a group, but they don't have any input into who they get.
12 acts make it through to the live shows, 4 from each group. At the end of each results show, the bottom 2 acts perform once again for the judges. With there being three judges, you can imagine the pressure on the third judge.
The British version was cool, because Sharon Osborne was one of the judges, and she really stood up to Simon. She was a lot better than Paula on AI. It was also cool to see people in their 30's and 40's who thought they had to give up on their dreams get a chance. They were usually very gracious and didn't throw tantrums like the young people in the auditions of AI.
If the American version stays true to the original format, than is anybody else looking forward to this show?