Who in there right mind would want to travel through Heathrow unless they had to!
Me, T5, redeveloped T4 and new T2 coming have changed the passenger experience greatly in recent years. STN is something of a pleasure to use as it was built for a more civilised era when the future was Air UK and Sterling Service. Even Sat 3 has to be the finest Ryanair facilities anywhere. Now I know there is no even playing field between both airfields but the superior facilities were put up by the BAA.
I think the issse is that the Ryanair driven bubble was unsustaniable given their reluctance to pay for use of.....anything frankly. Long haul was a long shot which leaves short haul, and Ryanair dominate. STN was a victim of an overnight success.