IMHO after a decade of flying on EK, the rules on carry on bags depend on the class of booking and your skywards status and also the airport you are travelling from.

On Y be prepared for the worst depending on the aiport of travel. More generous in J and with F you can literally get away with murder:-) as long as you don't break the size rule.

Even in the UK there are airports where they are very strict and weigh all hand luggage in Y like MAN and there are airports where they never weigh hand luggage (unless it looks very big)like LGW.