It was a year ago but when I used it the queue was very small, infact I was served straight away. I hand luggage only, so only used it for collecting my boarding pass but as I understand it you can check your bags there all the way to your final destination. I'll confirm that in August when I'm back out

I know there is a cutoff time per flight, which is about an hour/hour and half before take off, this allows for the train journey plus security etc