Stephen Thomas Erlewine's review: "the slick production and self-conscious maturity make X a leaden affair." (2.5 out of 5 stars)

Sion Smith's review: "Def Leppard have come up with their best body of work since Hysteria..." (4 out of 5 stars)

Malcolm Michaels' review: "Joe Elliott (whose voice has never sounded better), Rick Allen, Vivian Campbell, Rick Savage and Phil Collen have created pure ear candy and one of the best albums of the year." (9 out of 10)

Andy Capper's review: "Def Leppard improve with age: they lost their guitarist through drugs, their drummer had his arm amputated and, even though they're all in their 40s, they've just made the best rock album since Andrew WK's 'I Get Wet'."