But Simon Cowell says they're in for a treat when the show premieres its second season Wednesday on Fox (8 p.m. ET). "I've seen the first show and I think it's sensational," he told reporters recently during a conference call alongside Lovato.
"I think the girls do a great job and the contestants are great. The show looks different than anything we've ever made before." Spears, specifically, will keep viewers on their toes.
"[She] is a fascinating person because you just don't know anything about her," Cowell says. "She's very unpredictable. You never know what is going to happen. She has taken this very seriously and she's surprisingly quite mean." "In the past we've had judges that never say no," he continues. "[But] she can't say no quick enough on this show. She's quite difficult to please."