Have you evidence that the canaries were profitable and if they are so profitable why have Jet2 only added a quarter of the flights that EI offered last winter even though Jet 2 know that its a well established market for EI. I can think of a few factors that point to EI struggling on them last winter.
No numbers but I have spoken to someone from Aer Lingus staff who told me that the routes are profitble (if not exactly earth shatteringly so) although they do sell well so the potential to maximise profit should be there. I would suggest that the Jet2 frequencies are more to do with their cautious approach to expansion (especially if EI do surprise everyone and stay where they are)
To play devil's advocate, the same source told me that there are more 319s on the way and that they were considering uprating their (the 319s) engines.
I hold no sway toward either airport, as I said in my post, my personal view was that EI would move to city because they had some promised draw from the heathrow market. Not sure what to make of things now that BA has so publicly commited to the route from BHD using BA metal