I think the reason they have gone for the 72-500 is customer perception along with better reliability. To make the route sucessful they have to provide the busniess community with there best product. The 42's are old very loud and usually flown on sectors under 1 hour. I think with the 72'5 passenger will find it is the most comfortable option to and from the IOM.With ATR keen to certify the 72-600 for london city maybe the certification will certify all 72's after all they are more or less all the same with a few engine varitions.I believe Arann's despatch reliability has increased alot with the new a/c's so less chance of them having a technical problem and having a plane sitting in LCY for the day, I believe it is very expensive. I wish them all the sucess on the route and hope its just the start of more routes out of LCY in the future.