Regarding carry on baggage there are many things to consider. For starters it's not the size that causes queues at security but quantity. If Joe Bloggs turns up with one bag fine but usually he will have a bag, a boots carrier bag, a whsmith bag, a computer bag and then suddenly remember his mobile in his pocket which gives a total of 5 items being xrayed, no wonder there are queues. Hold luggage should not be screened through the usual hand luggage system by DFT regulations.Hold luggage screening is often done by a different company to the hand luggage so the staff can't swop around to help with any queues, and boy there will be some corkers come summer.