Simon Cowell is speaking out about Britney Spears‘ VMA act.

“It wasn’t the best performance…she looked like she was somewhere else. She wasn’t ready for it,” Cowell tells Extra. But the American Idol judge give Brit props for being a scene stealer. “She stole the show whether you liked it or not. The only thing you heard about the following day was Britney Spears.”

Simon says he would have kept Brit away from Sin City in the days leading up to her highly anticipated comeback. “I certainly wouldn’t have kept her in Vegas for three days beforehand. I would have put her in somewhere like Omaha. Rehearse, get her in there as quickly as possible, and get out.”

As for Brit’s belly-bearing bikini, Cowell blasts, “She should have had a very large snake on her to draw the attention away. She should have brought that snake back. It wasn’t a great outfit. It was appalling.”

Cowell’s suggestion to Brit: “Dump her friends…fire the stylist…be sensible…put her in rehearsal for four weeks, get her into the gym.” After all, he says, “When she’s on it, she’s incredible.”