LTNman
Your comments seem to suggest that any airport operating at less than full capacity would automatically have won top spot in the Which? survey.
I don't think that's true as SEN will, for example, only have staffing levels that match its current throughput and won't have spare staff just waiting around to be extra helpful. The fact that Stobart control most things that affect the customer experience and can put staff in the right place as demand dictates is probably one of its main advantages. They also, for example, provide adequate seating in the departure lounge whereas SEN's competitors are obsessed with herding people into shopping malls and keeping them there until the last possible moment. It seems that the latter model isn't what most travellers want to experience.
The fact that SEN scored 84% satisfaction while LCY scored only 68% in second place shows a wide gulf between the best and everyone else. That cannot be explained away simply by saying that SEN has a smaller throughput.