I just received my ABS and it's wrong by over £1000 (added pension payments missed, incorrect pensionable earnings). This is probably related to the fact that I changed employer within the CS this year- they appear only to have counted my pensionable earnings at my previous employer and only my added pension at my current employer. A complete mess.
Anyway, obviously you should always check it but this year in particular you might want to have a proper look given what a shitshow the year has been.