If I recall Manx2 did IOM STN for a stint too. Though on a LET 10!!
Though I cannot comment on flying between IOM and STN, I have views on the said London airports and airlines. I used to use STN a lot but I don't anymore. Primarily as many times I've arrived at STN on a weekend and the train is cancelled due to engineering works and ticket I pre booked account allowed on bus service. Coming back up from LPL Street same story one Sunday and the replacement bus must had 300 people queuing. I was totally last minute arriving at STN... That won't happen again. I actually wouldn't have minded if the train company had been honest and advised at time of booking online of these 'planned engineering work's.
The prices are often as expensive on the STN express as my plane ticket... And in net terms of cost the total to get to STN is most expensive of all the London airports.
EasyJet I always find superb, and very punctual.
But at the IOM I accept the schedule is not the most business orientated. However, fair to say that easyJet started IOM when Flybe had a good business schedule... Their focus was on the leisure passenger in the main, and with a lack of morning schedules into LGW and a need for an overnighter at IOM, it would appear that they will best see the opportunity for leisure passengers...
They will stick around, and BA unlikely to bow out to BE, I think STN will be canned, I'd give it another season at best. BE are revamping the winter schedule before it is issued, the best IOM can expect is that STN gets maintained.