As commented by some previous posters...
...And when will the Airport Operators actually invest properly the Security Surcharge that most of them have apparently been pocketing over the last few years...
Get all the security lines fully open, fully staffed, fully operational etc. etc. LHR/LGW I have never seen this happen - dont hold/inconvenience me and/or my customers in long lines as YOU the airport operator cant provide a fundamental service/task to the levels required by yr throughput YOU the airport operator charge me the airline (and so the customer) for every head so about time you provided the required true capacity per head
5 years of bsh!t excuses from them as to why they cant/how etc. is getting a bit thin
On the actual point of hand luggage size as an operator I am all for restrictions albeit this one does seem a tad to small - I am sick and tired of finding my bins broken and/or full with giant holdalls and other such items (particularly apparent in the USA it seems)